Παραπομπή σε μορφή APA (7η εκδ.)

Williams, D. B. (1968). Agricultural extension : farm extension: Services in Australia, Britain and the united states of America. Melbourne U.Pr.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Williams, Donald B. Agricultural Extension : Farm Extension: Services in Australia, Britain and the United States of America. Carlton, Vic: Melbourne U.Pr, 1968.

Παραπομπή σε μορφή MLA (9th εκδ.)

Williams, Donald B. Agricultural Extension : Farm Extension: Services in Australia, Britain and the United States of America. Melbourne U.Pr, 1968.