Template:Bechly et al., 1998
- Bechly, G., Nel, A., Martínez-Delclòs, X. & Fleck, G. 1998. Four new dragonfly species from the Upper Jurassic of Germany and the Lower Cretaceous of Mongolia (Anisoptera: Hemeroscopidae, Sonidae, and Proterogomphidae fam. nov.). Odonatologica 27(2): 149–187. PDF.