Gmelin Handbook: Ag: MVol.B5, 2.1, page 120 - 121 Full Text Show Details General Tire & Rubber Co. Patent: US2630444 , 1953 ; C. A., 1953 , p. 6102 Full Text Show Details General Tire & Rubber Co. Patent: US2630444 , 1953 ; C., 1954 , p. 3799