APA (7th ed.) Citation

OCLC. (1993). OCLC systems and services. EMERALD.

Chicago Style (17th ed.) Citation

OCLC. OCLC Systems and Services. Bradford, West Yorkshire, England: EMERALD, 1993.

MLA (9th ed.) Citation

OCLC. OCLC Systems and Services. EMERALD, 1993.

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