The excellent lecture videos of “Introduction to Abstract Algebra“, taught by Prof Benedict Gross at Harvard, can be downloaded here:
I met Prof Benedict Gross in Singapore last year at the NUS Public Lecture. I thanked him for these Abstract Algebra videos recorded many years earlier which helped me to understand and follow this advanced public lecture on “Elliptic Curve”. He was thrilled that remotely he could influence an unknown student through his Internet lectures.
Ref Books : Two Masterpieces on Abstract Algebra:
1) Written by MIT Prof, used by Harvard Prof Gross in this Online Course
2) Classical Approach:
Abstract Algebra, 3rd Edition