Autor:	Leon, Ronald P., Hedlund, Tammy, Meech, Sandra J., Li, Shaobing, Schaack, Jerome, Hunger, Stephen P., Duke, Richard C., DeGregori, James
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America, 1998 Oct . 95(22), 13159-13164.
Databáze:	JSTOR Journals
Externí odkaz:	https://www.jstor.org/stable/46212 Zobrazit plný text záznamu