Mammillaria - E-mail group group for discussion about the genus Mammillaria and it's relatives. Subscription management, archives, and shared files. groups.yahoo.com/group/Mammillaria
Mammillaria - Images of nine species. www.cacti.co.il/shmyel_mam.htm
Mammillaria Society - Promotes the study of the cactus genus Mammillaria, and also Coryphantha and allied genera such as Escobaria, Thelocactus, Gymnocactus, and Neolloydia. www.cactus-mall.com/mammsoc
