Pawlikowski, T., and K. Pawlikowski. “PHENOLOGY OF SOCIAL WASPS (HYMENOPTERA: VESPINAE) IN THE KUJAWY REGION (NORTHERN POLAND) UNDER THE INFLUENCE OF CLIMATIC CHANGES 1981–2000”. Bulletin of Geography. Physical Geography Series, no. 1, June 2009, pp. 125-34, doi:10.2478/2314.