Artikel in Cactus and Succulent Journal, The Journal of the Cactus and Succulent Society of America, 2016, Volume 88, No. 1, Seite 23-29
Hiking & Cacti – In search of Echinocereus chloranthus subsp. rhyolithensis in the Cookes Mountains, New Mexico
Autor: Gerhard & Gisela Böhm