Williams, D. B. (1968). Agricultural extension : farm extension: Services in Australia, Britain and the united states of America. Melbourne U.Pr.
Citazione stile Chigago Style (17a edizione)Williams, Donald B. Agricultural Extension : Farm Extension: Services in Australia, Britain and the United States of America. Carlton, Vic: Melbourne U.Pr, 1968.
Citatione MLA (9a ed.)Williams, Donald B. Agricultural Extension : Farm Extension: Services in Australia, Britain and the United States of America. Melbourne U.Pr, 1968.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.