2 literature references for Rhammatocerus variabilis (Bruner, L., 1900):

Author: Bruner, L.
Year: 1900
Title:
Source: Second Report of the Merchants' Locust Investigation Commission of Buenos Aires, Lincoln (NE) 80 pp.
Author: Jago
Year: 1971
Title: A review of the Gomphocerinae of the world with a key to the genera (Orthoptera: Acrididae)
Source: Proceedings of the Academy of Natural Sciences, Philadelphia (Proc. Acad. Nat. Sci. Philad.) 123:205-343