APA (7th ed.) Citation

(1989). World guide to libraries (9. ed.). <<de>> Gruyter Saur.

Chicago Style (17th ed.) Citation

World Guide to Libraries. 9. ed. Berlin: <<de>> Gruyter Saur, 1989.

MLA (9th ed.) Citation

World Guide to Libraries. 9. ed. <<de>> Gruyter Saur, 1989.

Warning: These citations may not always be 100% accurate.