Dąbrowski, W. 2008. Investigating Non-Governmental Organisations Cooperating Across the European Union External Border. Examples from Polish-Russian (Kaliningrad Oblast) And Polish-Ukrainian Border Regions. Bulletin of Geography. Socio-economic Series. 10 (Dec. 2008), 5–20. DOI:https://doi.org/10.1515/v10089-008-0009-3.