Hinton G. S., Turbinicarpus booleanus (Cactaceae), a new species from Nuevo Leon, Mexico, Phytologia, 1996, 80(1):62-66
The original description of the species from gypsum slopes in Nuevo León, now Rapicactus booleanus. It contains a diagnosis, measurements of the body, underground neck and thickened root, spine number and arrangement, and descriptions of the flower and fruit. It compares its structure and habitat with R. mandragora and R. subterraneus, named as Turbinicarpus in the paper. It documents the type collection from 1992, two localities known at the time and the origin of the species epithet.