Bieniecki, Ireneusz. “The Training Courses and Use of the Service Dogs in the Protection of the Polish Borders (1945–1991)”. The study of Security, no. 1 (October 31, 2016): 113–128. Accessed October 29, 2026. https://zeszyty-bn.upsl.edu.pl/index.php/snb/article/view/44.