1. American Society for Testing and Materials, Annual Book of ASTM Standards; “Standard method of tumble test for coke”; part 26, D294-64, 41-42 (1964).
2. American Society for Testing and Materials, Annual Book of ASTM Standards; “Standard test method for plastic properties of coal by the constant-torque Gieseler Plastometer”; D2639-74, 327-333 (1977).