Metzing, D. 2021: Revisions of Frailea, Gymnocalycium and various other genera. – In: Korotkova N. & al., Cactaceae at Caryophyllales.org – a dynamic online species-level taxonomic backbone for the family. – Willdenowia 51: 251-270

Title	Revisions of Frailea, Gymnocalycium and various other genera. – In: Korotkova N. & al., Cactaceae at Caryophyllales.org – a dynamic online species-level taxonomic backbone for the family
Authorship	Metzing, D.
Date published	2021
Volume	51
In journal	Willdenowia
Pages	251-270
Doi	http://doi.org/10.3372/wi.51.51208