The CIA World Factbook Volume 2: Full-Size 2019 Edition: Giant Format, 600+ Pages: The #1 Global Reference, Complete & Unabridged - Vol. 2 of 3, The Gambia ~ Poland (Carlile Intelligence Library):
First US Troops Arrive In Poland To Reinforce NATO Allies In Eastern Europe – Eurasia Review
World - The World Factbook
File:CIA World Map Political 2021.pdf - Wikimedia Commons
Poland - The World Factbook
File:CIA World Factbook 2016-17 Cover.jpg - Wikimedia Commons