Dyfyniad APA

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

Dyfyniad Arddull Chicago

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

Dyfyniad MLA

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

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.