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. |