Template:Vetter & Visscher, 1997
- Vetter, R.S.; Visscher, P.K. 1997: Plasticity of annual cycle in Vespula pensylvanica shown by a third year polygynous nest and overwintering of queens inside nests. Insectes sociaux 44(4): 353-364. DOI: 10.1007/s000400050057