Παραπομπή APA

hartwick, J. M. (1989). Non-Renewable resources extraction programs and markets. Harwood academic Pub.

Παραπομπή Chicago Style

hartwick, John M. Non-Renewable Resources Extraction Programs and Markets. Chur: Harwood academic Pub, 1989.

Παραπομπή MLA

hartwick, John M. Non-Renewable Resources Extraction Programs and Markets. Harwood academic Pub, 1989.