Mcdonald, D. E., H. Ruhberg, and S. R. Daniels. “Two New Peripatopsis Species (Onychophora: Peripatopsidae) from the Western Cape Province, South Africa”. Zootaxa, vol. 3380, no. 1, July 2012, pp. 55–68, doi:10.11646/zootaxa.3380.1.4.