LICENSE: Switch to CC-BY-SA-4.0

Closes #18.

Author: stefan6419846

LICENSE

@@ -1,4 +1,4 @@
-Attribution-NonCommercial-NoDerivatives 4.0 International
+Attribution-ShareAlike 4.0 International
 
 =======================================================================
 
@@ -54,18 +54,18 @@ exhaustive, and do not form part of our licenses.
 
 =======================================================================
 
-Creative Commons Attribution-NonCommercial-NoDerivatives 4.0
-International Public License
+Creative Commons Attribution-ShareAlike 4.0 International Public
+License
 
 By exercising the Licensed Rights (defined below), You accept and agree
 to be bound by the terms and conditions of this Creative Commons
-Attribution-NonCommercial-NoDerivatives 4.0 International Public
-License ("Public License"). To the extent this Public License may be
-interpreted as a contract, You are granted the Licensed Rights in
-consideration of Your acceptance of these terms and conditions, and the
-Licensor grants You such rights in consideration of benefits the
-Licensor receives from making the Licensed Material available under
-these terms and conditions.
+Attribution-ShareAlike 4.0 International Public License ("Public
+License"). To the extent this Public License may be interpreted as a
+contract, You are granted the Licensed Rights in consideration of Your
+acceptance of these terms and conditions, and the Licensor grants You
+such rights in consideration of benefits the Licensor receives from
+making the Licensed Material available under these terms and
+conditions.
 
 
 Section 1 -- Definitions.
@@ -80,59 +80,63 @@ Section 1 -- Definitions.
      Adapted Material is always produced where the Licensed Material is
      synched in timed relation with a moving image.
 
-  b. Copyright and Similar Rights means copyright and/or similar rights
+  b. Adapter's License means the license You apply to Your Copyright
+     and Similar Rights in Your contributions to Adapted Material in
+     accordance with the terms and conditions of this Public License.
+
+  c. BY-SA Compatible License means a license listed at
+     creativecommons.org/compatiblelicenses, approved by Creative
+     Commons as essentially the equivalent of this Public License.
+
+  d. Copyright and Similar Rights means copyright and/or similar rights
      closely related to copyright including, without limitation,
      performance, broadcast, sound recording, and Sui Generis Database
      Rights, without regard to how the rights are labeled or
      categorized. For purposes of this Public License, the rights
      specified in Section 2(b)(1)-(2) are not Copyright and Similar
      Rights.
 
-  c. Effective Technological Measures means those measures that, in the
+  e. Effective Technological Measures means those measures that, in the
      absence of proper authority, may not be circumvented under laws
      fulfilling obligations under Article 11 of the WIPO Copyright
      Treaty adopted on December 20, 1996, and/or similar international
      agreements.
 
-  d. Exceptions and Limitations means fair use, fair dealing, and/or
+  f. Exceptions and Limitations means fair use, fair dealing, and/or
      any other exception or limitation to Copyright and Similar Rights
      that applies to Your use of the Licensed Material.
 
-  e. Licensed Material means the artistic or literary work, database,
+  g. License Elements means the license attributes listed in the name
+     of a Creative Commons Public License. The License Elements of this
+     Public License are Attribution and ShareAlike.
+
+  h. Licensed Material means the artistic or literary work, database,
      or other material to which the Licensor applied this Public
      License.
 
-  f. Licensed Rights means the rights granted to You subject to the
+  i. Licensed Rights means the rights granted to You subject to the
      terms and conditions of this Public License, which are limited to
      all Copyright and Similar Rights that apply to Your use of the
      Licensed Material and that the Licensor has authority to license.
 
-  g. Licensor means the individual(s) or entity(ies) granting rights
+  j. Licensor means the individual(s) or entity(ies) granting rights
      under this Public License.
 
-  h. NonCommercial means not primarily intended for or directed towards
-     commercial advantage or monetary compensation. For purposes of
-     this Public License, the exchange of the Licensed Material for
-     other material subject to Copyright and Similar Rights by digital
-     file-sharing or similar means is NonCommercial provided there is
-     no payment of monetary compensation in connection with the
-     exchange.
-
-  i. Share means to provide material to the public by any means or
+  k. Share means to provide material to the public by any means or
      process that requires permission under the Licensed Rights, such
      as reproduction, public display, public performance, distribution,
      dissemination, communication, or importation, and to make material
      available to the public including in ways that members of the
      public may access the material from a place and at a time
      individually chosen by them.
 
-  j. Sui Generis Database Rights means rights other than copyright
+  l. Sui Generis Database Rights means rights other than copyright
      resulting from Directive 96/9/EC of the European Parliament and of
      the Council of 11 March 1996 on the legal protection of databases,
      as amended and/or succeeded, as well as other essentially
      equivalent rights anywhere in the world.
 
-  k. You means the individual or entity exercising the Licensed Rights
+  m. You means the individual or entity exercising the Licensed Rights
      under this Public License. Your has a corresponding meaning.
 
 
@@ -146,10 +150,9 @@ Section 2 -- Scope.
           exercise the Licensed Rights in the Licensed Material to:
 
             a. reproduce and Share the Licensed Material, in whole or
-               in part, for NonCommercial purposes only; and
+               in part; and
 
-            b. produce and reproduce, but not Share, Adapted Material
-               for NonCommercial purposes only.
+            b. produce, reproduce, and Share Adapted Material.
 
        2. Exceptions and Limitations. For the avoidance of doubt, where
           Exceptions and Limitations apply to Your use, this Public
@@ -179,7 +182,13 @@ Section 2 -- Scope.
                Licensed Rights under the terms and conditions of this
                Public License.
 
-            b. No downstream restrictions. You may not offer or impose
+            b. Additional offer from the Licensor -- Adapted Material.
+               Every recipient of Adapted Material from You
+               automatically receives an offer from the Licensor to
+               exercise the Licensed Rights in the Adapted Material
+               under the conditions of the Adapter's License You apply.
+
+            c. No downstream restrictions. You may not offer or impose
                any additional or different terms or conditions on, or
                apply any Effective Technological Measures to, the
                Licensed Material if doing so restricts exercise of the
@@ -211,9 +220,7 @@ Section 2 -- Scope.
           Rights, whether directly or through a collecting society
           under any voluntary or waivable statutory or compulsory
           licensing scheme. In all other cases the Licensor expressly
-          reserves any right to collect such royalties, including when
-          the Licensed Material is used other than for NonCommercial
-          purposes.
+          reserves any right to collect such royalties.
 
 
 Section 3 -- License Conditions.
@@ -223,7 +230,8 @@ following conditions.
 
   a. Attribution.
 
-       1. If You Share the Licensed Material, You must:
+       1. If You Share the Licensed Material (including in modified
+          form), You must:
 
             a. retain the following if it is supplied by the Licensor
                with the Licensed Material:
@@ -251,9 +259,6 @@ following conditions.
                Public License, and include the text of, or the URI or
                hyperlink to, this Public License.
 
-          For the avoidance of doubt, You do not have permission under
-          this Public License to Share Adapted Material.
-
        2. You may satisfy the conditions in Section 3(a)(1) in any
           reasonable manner based on the medium, means, and context in
           which You Share the Licensed Material. For example, it may be
@@ -265,6 +270,25 @@ following conditions.
           information required by Section 3(a)(1)(A) to the extent
           reasonably practicable.
 
+  b. ShareAlike.
+
+     In addition to the conditions in Section 3(a), if You Share
+     Adapted Material You produce, the following conditions also apply.
+
+       1. The Adapter's License You apply must be a Creative Commons
+          license with the same License Elements, this version or
+          later, or a BY-SA Compatible License.
+
+       2. You must include the text of, or the URI or hyperlink to, the
+          Adapter's License You apply. You may satisfy this condition
+          in any reasonable manner based on the medium, means, and
+          context in which You Share Adapted Material.
+
+       3. You may not offer or impose any additional or different terms
+          or conditions on, or apply any Effective Technological
+          Measures to, Adapted Material that restrict exercise of the
+          rights granted under the Adapter's License You apply.
+
 
 Section 4 -- Sui Generis Database Rights.
 
@@ -273,13 +297,13 @@ apply to Your use of the Licensed Material:
 
   a. for the avoidance of doubt, Section 2(a)(1) grants You the right
      to extract, reuse, reproduce, and Share all or a substantial
-     portion of the contents of the database for NonCommercial purposes
-     only and provided You do not Share Adapted Material;
+     portion of the contents of the database;
 
   b. if You include all or a substantial portion of the database
      contents in a database in which You have Sui Generis Database
      Rights, then the database in which You have Sui Generis Database
-     Rights (but not its individual contents) is Adapted Material; and
+     Rights (but not its individual contents) is Adapted Material,
+     including for purposes of Section 3(b); and
 
   c. You must comply with the conditions in Section 3(a) if You Share
      all or a substantial portion of the contents of the database.
@@ -380,6 +404,7 @@ Section 8 -- Interpretation.
      that apply to the Licensor or You, including from the legal
      processes of any jurisdiction or authority.
 
+
 =======================================================================
 
 Creative Commons is not a party to its public

README.md

@@ -8,7 +8,7 @@ The `files.json` file contains a list of those PDF files with their metadata.
 ## Licenses
 
 Every PDF in this repository is under the Creative Commons
-Attribution-NonCommercial-NoDerivs License (CC BY-NC-ND).
+Attribution-ShareAlike License (CC-BY-SA-4.0).
 
 
 ## Contributions