Hoffman, R. L. (2011). A review of the milliped genus Haplogonopus with commentary on the so-called “Charactopygus-Bildung” modification of spirostreptid paraprocts (Diplopoda: Spirostreptidae). Zootaxa, 2734(1), 53–62. https://doi.org/10.11646/zootaxa.2734.1.4