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 (Jan. 2011), 53–62. DOI:https://doi.org/10.11646/zootaxa.2734.1.4.