APA (7 ম সংস্করণ) উদ্ধৃতি

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

শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতি

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

M.L.A (9 ম সংস্করণ) উদ্ধৃতি

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