P.A. Luty 9 mm sub-machine guns - Armament Research Services (ARES)
Grease Gun Storage : 7 Steps - Instructables
Grease Gun: Examining the M3/M3A1 Submachine Gun
Bootleg Gunz:The Bazaar of Bizarre Guns - "A .45 homemade submachine gun made by Ulster loyalist paramilitaries held in a Greater Manchester police armoury. It appears to use an M3 Grease Gun