Skuhravá, M., Skuhravý, V., Jøgensen, J., (2006). Entomologiske Meddelelser 74(Special Issue), 1-94. Entomologisk Forening i København, Copenhagen, Denmark. Danish language
Shea, P. J., (1989). Canadian Entomologist 121(8), 699-708. English language
Shea, P. J., (1989). Oecologia 81(1), 104-110. English language