found: Work cat.: Owers, C. Late Gotha bombers, 2010.
found: Hutchinson encyclopedia website, 23 Nov. 2010:under Gotha bomber (German twin-engined biplane bomber, the principal strategic bomber of the German air force in World War I from 1917 onwards; although early models, G1 and G2, were used on the Balkan and Eastern Fronts as tactical bombers they were unreliable and it was not until the G4 that Gotha became the standard heavy bomber for raids over England and France)
found: First World War.com, 23 Nov. 2010:war in the air, bombers, Germany (in the autumn of 1916 the Germans began to equip with the Gotha twin engined bomber; these aircraft could fly at 15,000 feet, above contemporary fighter's maximum height; with a range of 500 miles and a bomb load of up to 1,100lb, the Gothas were designed to carry out attacks across the channel against Britain)
