Number Theory
- G. H. Hardy, E.M. Wright, An Introduction to the Theory of Numbers, Oxford University Press.
- Ivan Niven, Herbert S Zuckerman, Hugh L Montgomery, An Introduction to the Theory of Numbers, John Wiley & Sons.
- Kenneth H. Rosen, Elementary number theory and its applications, Addison-Wesley Publishing Company.
- W. Sierpinski, Elementary Theory of Numbers, North Holland.
- W. Sierpinski, 250 Problems in Elementary Number Theory, Elsevier Publishing Company.
- David M. Burton, Elementary Number Theory, McGraw Hill.
- Thomas Koshy, Elementary Number Theory with Applications; Elsevier Publishing Company.
Inequalities
G. H. Hardy, E.M. Wright, An Introduction to the Theory of Numbers, Oxford University Press.
B. J. Venkatachala, Inequalities – an approach through problems, Springer.
Radmila Bulajich Manfrino, Jose Antonio Ortega, Rogelio Valdez Delgado, Inequalities – A Mathematical Olympiad Approach, Birkhäuser.