Update README.md

Author: ipeirotis

README.md

@@ -17,11 +17,6 @@ This is a set of notes used for teaching Python to students that have never used
 
 * [Videos for the class](https://www.youtube.com/playlist?list=PLqAPn_b_yx0TBDqe5-AMSed6sYzMj9qkN)
 
-## Exercises for `nbgrader` (for Educators)
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-* If you would like to get access to the autograded assignments that we have developed, please contact me at `panos@stern.nyu.edu`.
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 ## Recommended Books
 
 * [Python for Everybody: Exploring Data In Python 3](https://www.py4e.com/book): This is a textbook for students that are learning Python as their first programming language, with the objective of using programming to handle and analyze data. 
@@ -31,7 +26,7 @@ This is a set of notes used for teaching Python to students that have never used
 ## Additional Books for Learning Python
 
 * [How To Think Like a Computer Scientist](https://runestone.academy/ns/books/published/thinkcspy/index.html): An interactive guide to programming and Python. The book "Python for Everybody" (listed above) is partially based on this book.
-* [Learn Python the Hard Way](https://learnpythonthehardway.org/python3/): An introduction to programming and Python. It targets complete beginners. It used a drill-based approach for teaching, which can be tedious at times. Nevertheless, it is considered one of the standard textbooks for learning Python.
+* [Learn Python the Hard Way](https://learnpythonthehardway.org/python3/): An introduction to programming and Python. It targets complete beginners. It uses a drill-based approach for teaching, which can be tedious at times. Nevertheless, it is considered one of the standard textbooks for learning Python.
 
 ## Online Classes