@BOOK{ Book!D - 100986023,
AUTHOR = "/ Titu Andreescu, Razvan Gelca ",
TITLE = "Mathematical Olympiad challenges",
LIBRARY= "كتابخانه پردیس علوم (دانشگاه تهران)",
SUBJECT = "Mathematics -- Problems, exercises, etc.",
URL = "/book/100986023/Mathematical-Olympiad-challenges/"}