The Power of Your Subconscious Mind by Joseph Murphy

Higher Algebra by H. S. Hall, S. R. Knight
Higher Algebra by S. Barnard, J. M. Child
Thomas' Calculus by George B Thomas, Maurice D Weir, Joel Hass, Frank R Giordano
Plane Trigonometry by S. L. Loney
Co-ordinate Geometry by S. L. Loney
Calculus in One Variable by I. A. Maron
Encyclopedia of Mathematics by Eric Weisstein
Elementary Linear Algebra by Howard Anton
The World of Mathematics by James R. Newman
Engineering Mathematics by B. S. Grewal
Men in Mathematics by E. T. Bell
One Two Three ... Infinity by George Gamow
Introductory Methods of Numerical Analysis by S. S. Sastry
Real Life Math by Evan M. Glazer, John W. McConnell

CodeChef
GeeksforGeeks
Careercup
LeetCode
Problems on Algorithms by Ian Parberry
Algorithmic Puzzles by Anany Levitin, Maria Levitin
Algorithms for Interviews by Adnan Aziz and Amit Prakash
Cracking the Coding Interview by Gayle Laakmann McDowell
Programming Interviews Exposed by John Mongan and Noah Suojanen

Introduction to the Design and Analysis of Algorithms by Anany Levitin
Introduction to Algorithms by Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, Clifford Stein
The Algorithm Design Manual by Steven Skiena
Algorithms by S. Dasgupta, C. H. Papadimitriou, U.V. Vazirani
Fundamentals of Computer Algorithms by Ellis Horowitz, Sartaj Sahni, Sanguthevar Rajasekaran

Brain Teasers by Ravi Narula
Wu Riddles
Wikipedia
A Mathematical Mosaic by Ravi Vakil
My Best Mathematical and Logic Puzzles by Martin Gardner
Mathematical Puzzles by Peter Winkler
Famous Puzzles of Great Mathematicians by Miodrag S. Petkovic
Amusements in Mathematics by Henry Ernest Dudeney
Fifty Challenging Problems in Probability with Solutions by Frederick Mosteller
Nick's Mathematical Puzzles

The C Programming Language by Brian W. Kernighan and Dennis M. Ritchie
The C Complete Reference by Herbert Schildt
The C++ Complete Reference by Herbert Schildt
The Java Complete Reference by Herbert Schildt