Literature references

1 literature reference for Orthetrum nigrescens Foerster, 1906:

Author: Foerster, F.
Year: 1906
Title: Die Libellengattungen von Afrika und Madagaskar. [Date important since several species also described in Jb Nass Ver Ntk 59; I presume present publication has priority]
Source: Jahresbericht des Mannheimer Vereins für Naturkunde: 71/72: s1-s67.