Παραπομπή APA

(1977). World Book Year Book: The annual Supplement to the workld book encyclopedia. Field Enterprise.

Παραπομπή Chicago Style

World Book Year Book: The Annual Supplement to the Workld Book Encyclopedia. Chicago: Field Enterprise, 1977.

Παραπομπή MLA

World Book Year Book: The Annual Supplement to the Workld Book Encyclopedia. Field Enterprise, 1977.