1943, TM5-3020, War Department, Maintenance Manual and Parts Catalog; Tractor, Crawler Type, Gasoline, 20 DBHP, with Bulldozer and Towing Winch, Model CA-1 “Clarkair” & TM5-1270 Bulldozer Hydraulic Tractor Mounted , 59 Inch Blade , Model BABX For Model CA-1 Clarkair Crawler.(2)