Railway Gun: Most Up-to-Date Encyclopedia, News & Reviews

M1911 Pistol: Most Up-to-Date Encyclopedia, News & Reviews

Electronics, Free Full-Text

Dora Railway Gun, Turtledove

Schwerer Gustav - Wikipedia

First seen during the American Civil War and later appearing in the Franco-Prussian War and the Anglo-Boer Wars, the armored train came to prominence

Armored Trains (New Vanguard, 140)

File:Ex-French 274 cm K.E 592 f railway gun with number 929323 and

Railway Gun: Most Up-to-Date Encyclopedia, News & Reviews

Stratford Works: Most Up-to-Date Encyclopedia, News & Reviews

railway gun - Wiktionary, the free dictionary

Railway Guns of World War II (New Vanguard, 231): Zaloga, Steven J