The Ruby programming Language: o’Reilly. $ 15
Agile Web Development with Rails Thomas and Hanson: $ 12
Automata Theory, Languages and Computation: Hopcroft, Motwani and Ullman $ 65
CS 110: Principles of computer systems vol 1 and 2: spring 2009 - $10 each
A course in Combinatorics Second Edition: J.H. Van Lint and R. M Wilson: $ 25
Electrical Engineering- Principles and Applications - Allan R. Hambley $10