Calculus of variations
Abstract Algebra (Herstein 3rd Ed)
Finite Group Theory-Martin Isaac
Cryptography and Data Security
Sage Tutorial
Arthur, Merlin, and Black-Box Groups in Quantum Computing Scott Aaronson (MIT) Or, How Laci Did Quantum Stuff Without Knowing It.
Iyanaga S. - Algebraic Number Theory
Sage tutorial
Group theory
[Cabanes M., Enguehard M.] Representation Theory o(BookFi.org)