1-4 of 4 Books
Introduction to algorithms
By Udi Manber
Fractals, chaos, power laws
By M. R. Schroeder
Fundamentals of Computer Programming with CSharp Free Book (by Nakov & Co.)
By Svetlin Nakov
Ŏnŏ wa inji ŭi sunhwansŏng kwa kiwŏn
By Suk-hwan Cho