Since its time as the Library of Imperial University of Peking, Peking University Library has placed great importance on the introduction of Western books. Over the years, through extensive accumulation and with its incorporation of collections from the former Yenching University, Sino-French University, and Sino-German Society, the library has amassed an impressive collection of books in foreign languages, ranking at the top among all university libraries in China. PKU Library currently holds thousands of rare books in foreign languages, the earliest publication being the Greek edition of Euclid's Elements published in Basel, Switzerland in 1533. Much of the collection features Sinology, including both major works of China Studies and translations of Chinese classics.