Autor:	Swallen, Jason R., Rappleye, Howard S., Morrison, Joseph P. E., Schubauer, Galen B., Walker, Egbert H., Stevenson, John A., Ewers, John C., Cook, Richard K., Chace, Fenner A., Rehder, Harald A., Specht, Heinz, McPherson, A. T., Gibson, Ralph E., Rubey, William W.
Zdroj:	Journal of the Washington Academy of Sciences, 1955 Mar 01. 45(3), 86-97.
Databáze:	JSTOR Journals
Externí odkaz:	https://www.jstor.org/stable/24533243 Zobrazit plný text záznamu