Väänänen, S., Paukkunen, J., Soon, V. and Budrys, E. 2018. Occurrence and biology of Pseudogonalos hahnii (Spinola, 1840) (Hymenoptera: Trigonalidae) in Fennoscandia and the Baltic states. Entomologica Fennica. 29, 2 (Jun. 2018), 86–96. DOI:https://doi.org/10.33338/ef.71220.