Verbatim text: Zimmerman, A. D. and D. A. Zimmerman. 1977. A revision of the United States taxa of the Mammillaria wrightii complex with remarks upon the northern Mexican populations. Cact. Succ. J. (Los Angeles) 49: 23–34, 51–62.
Author: Zimmerman, A.D., Zimmerman, D.A.
Year: 1977
Title: A revision of the United States taxa of the Mammillaria wrightii complex with remarks upon the northern Mexican populations
Journal: Cact. Succ. J. (Los Angeles)
Volume: 49
Pages: 23–34, 51–62