1. Patent literature, eg Brit. Pats. 274416(1926), 287890 (1927),335833(1929),424687(1933),433467(1934), 489352(1936),514158(1938) and 543818(1941)
2. Rubber as a material for bearings;Brazier,1937
3. Some experiments with water-lubricated rubber bearings;Fogg,1937
4. Frictional properties of rubber;Roth;J. Res. Natl. Bur. Std. U.S.A.,1942
5. Influence of load and surface roughness on friction of rubber-like materials;Denny,1953