- The Attack of the "Dead Men" was a battle of World War I that took place at the Osowiec Fortress, in northeast Poland, on August 6, 1915.
- en-academic.com dic.nsf/enwiki/11865618Osowiec Fortress (Polish Twierdza Osowiec) - a 19th century fortress located in north-eastern Poland, originally built by the Russian Empire.
- The Battle of Osowiec Fortress served as the backdrop for an extraordinary event where Russian soldiers, condemned to death by gassing, chose to fight back.
- getslimsecret.com radiant/wiki/Osowiec_Fortress53°28′20″N 22°39′06″E / 53.47222°N 22.65167°E. Monument in Osowiec Fortress. Fort II of Osowiec Fortress. Soldiers outside the Osowiec fortress church, 1915.
- tracesofwar.com sights/38448/Fortress-Osowiec---…Fortress Osowiec - Fort I #4. This enormous fortress was constructed by the Russians from 1882 to 1892 and saw heavy fighting during the First World War.
- owiki.org wiki/Osowiec_FortressOsowiec Fortress is a 19th-century fortress located in north-eastern Poland, built by the Russian Empire.
- The Osowiec Fortress - Zabytek.pl. ... Complexe fortifié d'Osowiec — Wikipédia. The bunker was located on a hill in the exact centre of the Polish lines.
- commons.wikimedia.org wiki/Osowiec-TwierdzaEnglish: Osowiec-Twierdza is a town in the Podlasie Vojvodship in north-east Poland, in which there is a Osowiec Fortress. Headquarters - Biebrza National Park.
- OpenTripMap.com en/card/Q2503140Osowiec Fortress (Polish Twierdza Osowiec) is a 19th-century fortress built by the Russian Empire, located in what is now north-eastern Poland.