Gaya APA

Engel, J, R., Engel, J, G. (1990). Ethics of Enviroment And Development : Global Challenge and International Response . London: Bethaven Press.

Gaya MLA

Engel, J., Ronald., Engel, Joan, Gibb. "Ethics of Enviroment And Development : Global Challenge and International Response". London: Bethaven Press, 1990. Text.