المؤلفون: Derrick, Michele R., Stulik, Dusan C., Landry, James M., Bouffard, Steven P.

المصدر: Journal of the American Institute for Conservation, 1992 Jul 01. 31(2), 225-236.

URL الوصول: https://www.jstor.org/stable/3179494

المؤلفون: Derrick, Michele R., Doehne, Eric F., Parker, Andrew E., Stulik, Dusan C.

المصدر: Journal of the American Institute for Conservation, 1994 Jul 01. 33(2), 171-184.

URL الوصول: https://www.jstor.org/stable/3179425