Short list:

1. Problem primer for olympiads: C.R. Pranesachar, B J Venkatachala and C S
Yogananda (Prism Books Pvt Ltd, Jayangar, Bangalore)

2. Challenge and thrill of pre-college mathematics: V. Krishnamurthy, C R
Pranseachar, K N Ranganathan and B. J. Venkatachala (New age international
publishers, New Delhi)

3. An Excursion in Mathematics, Ed. M R Modak, S A Katre and V V Acharya
(Bhaskaracharya Pratishthana, Pune)

4. Functional Equations, B J Venkatachala (Prism Books Pvt Ltd, Jayanagar,

5. Mathematical Circles: Russian Experience (University Press, Hyderabad).

Long list:

1. Klamkin, M.S. U.S.A. Maths Olympiad, 1972 - 1986

2. Yaglom, I.M. The USSR Olympiad Problem Book (Dover)

3. Sierpenski. W 250 Problems in Elementary Number Theory (Elsevier)

4. Niven & Zukerman An Introduction to the theory of Numbers (Wiley)

5. Coxeter, H.S.M. Geometry Revisited (MAA)

6. Larson, L.C. Problem Solving through Problems (Springer)

7. Bottema. O. Geometric Inequalities (MAA)

8. V. Krishnamoorthy etal. Challenges and thrill of Precollege Mathematics (New Age Publ.)

9. Pranesachar C.R. Mathematical challenges from Olympiads. (Interline Publ)

10. Lozansky E., Rousseau, C Winning Solutions (Springer)

11. M.K. Singal, A.R. Singal Olympiad Mathematics (Pitambar Publ.)

12. S.A. Katre An excursion in Mathematics

13. V. Seshan Mastering Olympiad Mathematics (Frank Brothers)

14. Engel A. Problem Solving Strategies (Springer)

15. Shirali S. A First steps in Number Theory (Universities Press)

16. Shirali S.A. Adventures in Problem Solving ,, ,,

17. Steven G. Krantz Techniques of Problem Solving ,, ,,

18. Titu Andreescu & Mathematical Olympiad Challenges Razvan Gelca; (Universities Press)

19. Burton Elementary Number Theory (UBS)

20. Venkatachala B. J. Functional Equations. A problem solving approach

21. Durrell C. V. Geometry

22. Bonnie Averback and Problem solving through recreational Mathematics Oria Chein (Dover)

23. Alfred Posamentiar Challenging Problems in Geometry (Dover) and Charles T. Salkind

24. Beiler A.H. Recreations in the theory of numbers (Dover)

25. A Gardiner The Mathematical Olympiad Hand book OUP (2000)

26. T. Andreesan Mathematical Olympiad Challenges R. Gelca Birkhauser (2000)

27. S. Muralidharan Gems from the Mathematics Teacher, AMTI (1997) G.R. Vijayakumar

28. V.K. Krishnan (Ed.) Non-routine problems in Mathematics, AMTI (2000)

29. R. Roy Choudhary 501 Difficult problems in Mathematics, BM Pub (2000)

30. T. Andreescu Mathematical Olympiad Treasures, Birkhauser (2004)

31. Bernard and Child Higher Algebra (Mc Millan)

32. Stein haus One Hundred Problems in Elementary Mathematics (Dover)

33. Eves H. College Geometry (Narosa) (1995)

34. Williams K.S.; Hardy, K The red book of mathematical problems (Dover)

35. I. Reiman International Mathematics Olympiad Vol. I-III (Anthem Press)