Não informado. (2007). Report of the Penrose Research Laboratory. Zoological Society of Philadelphia.
Chicago-Zitierstil (17. Ausg.)Não informado. Report of the Penrose Research Laboratory. Philadelphia, Pa: Zoological Society of Philadelphia, 2007.
MLA-Zitierstil (8. Ausg.)Não informado. Report of the Penrose Research Laboratory. Zoological Society of Philadelphia, 2007.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.