Chentzov, N. N. books & textbook
The USSR Olympiad Problem Book: Selected Problems and Theorems of Elementary Mathematics (Dover Books on Mathematics)
Shklarsky, D. O. Chentzov, N. N. Yaglom, I. M.
Dover Publications /1993-09-28 Paperback / 480 Pages
isbn-10: 0486277097 / isbn-13: 9780486277097
The USSR Olympiad Problem Book
D O, Chentzov, N N and Yaglom, I M Shklarsky
W.H. Freeman /1962T Hardcover / 452 Pages
isbn-10: 0716704129 / isbn-13: 9780716704126
