Number Theory: Structures, Examples, and Problems

It's not a book for beginners in number theory, it's perfect for people who're interest in study for mathematical olympiads and those who're interest in study deeper number theory. It's a fantastic book, like most books of titu and Dorin Andrica, i recomend !

good

It's perfect to prefare math olympiad contest. It contains fundamental conceptsof elementary number theory and practical problems of math contests with originalsolutions.