The KV-3 was an early war Soviet heavy tank armed with the powerful new 107 mm ZiS-6 gun mounted on a modified version of the KV-220 hull.
Kliment Voroshilov tank - Wikipedia
KV-1 - Tank Encyclopedia
KV-3 (Object 223) - Tank Encyclopedia
Archives
WW2 Soviet KV-4 Archives - Tank Encyclopedia
KV-220 (Object 220/T-220) - Tank Encyclopedia
Soviet IS-III (1944)
KV-3 heavy tank
KV-3, Forgotten Hope Secret Weapon Wiki
KV-3 (Object 223) - Tank Encyclopedia