In Lucinda & Reis (2005) Systematics of the subfamily Poeciliinae Bonaparte (Cyprinodontiformes: Poeciliidae), with an emphasis on the tribe Cnesterodontini Hubbs. Neotropical Ichthyology, 3(1):1-60. PDF – taxon authority for Gambusiini is Gill, 1893:133 (pp. 2,36)
In Hubbs, C. L. (1924) Studies of the fishes of the order Cyprinodontes. Miscellaneous Publications, Museum of Zoology, University of Michigan 13: 1-31, Pls. 1-4. PDF – Gambusiini is listed as "New tribe name" (p.6).