1. Asphalt and Allied Substances;Abraham,1945
2. Standard Method of Test for Penetration of Bituminous Materials (D5–25);Am. Soc. Testing Materials,1942
3. Standard Method of Test for Softening Point of Bituminous Materials (Ring and Ball Method) (D36-26);Am. Soc. Testing Materials,1942
4. Standard Method of Test for Ductility of Bituminous Materials (D113-39);Am. Soc. Testing Materials,1942