Perwita, A. A. B., and W. D. Rachmawati. “The Modernization of Poland Defense Forces to Respond Russia Military Presence in Kaliningrad Oblast (2014-2017)”. Global Strategis, vol. 12, no. 1, June 2018, pp. 183-01, doi:10.20473/jgs.12.1.2018.183-201.