Montanucci, Richard R. “A Morphological Study on the Question of the Hybrid Origin of Astrophytum Coahuilense (Cactaceae)”. Journal of the Botanical Research Institute of Texas 18, no. 1 (July 9, 2024): 163–185. Accessed December 22, 2024. https://journals.brit.org/jbrit/article/view/1346.