APA (7e ed.) Bronvermelding

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

Chicago (17e ed.) Bronvermelding

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

MLA (9e ed.) Bronvermelding

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