Citazione Stile APA (7a Edizione)

Hart, R. D. An ecological systems conceptual framework for agricultural research and development.

Citazione stile Chigago Style (17a edizione)

Hart, Robert D. An Ecological Systems Conceptual Framework for Agricultural Research and Development. [Date of publication not identified].

Citatione MLA (9a ed.)

Hart, Robert D. An Ecological Systems Conceptual Framework for Agricultural Research and Development.

Attenzione: Queste citazioni potrebbero non essere precise al 100%.