E. J. Alexander: Ortegocactus a unique genus. In: Cactus and Succulent Journal. Band 33, Nummer 2, Los Angeles 1961, S. 39 (online).
doi.org
Peter B. Breslin, Martin F. Wojciechowski, Lucas C. Majure: Molecular phylogeny of the Mammilloid clade (Cactaceae) resolves the monophyly of Mammillaria. In: Taxon. Band 70, Nr. 2, 2021, S. 319 (doi:10.1002/tax.12451).
