15 Cm Sig 33 Kaynak
 

Kaynak

Chamberlain, Peter, and Hilary L. Doyle. Thomas L. Jentz (Technical Editor).
Encyclopedia of German Tanks of World War Two: A Complete Illustrated Directory of German Battle *Tanks, Armoured Cars, Self-propelled Guns, and Semi-tracked Vehicles, 1933-1945.
London: Arms and Armour Press, 1978 (revised edition 2004).
İngilizce Wikipedia 15 cm sIG 33 maddesi

Kaynak : Wikipedia