APA

American Society for Testing and Materials, ASTM STP 984, . (1988). Rock classification systems for engineering purposes. Philadelphia, PA: American Society for Testing and Materials.

Chicago

American Society for Testing and Materials, ASTM STP 984, . 1988. Rock classification systems for engineering purposes. Philadelphia, PA: American Society for Testing and Materials.

Harvard

American Society for Testing and Materials, ASTM STP 984, . (1988). Rock classification systems for engineering purposes. Philadelphia, PA: American Society for Testing and Materials.

MLA

American Society for Testing and Materials, ASTM STP 984, . Rock classification systems for engineering purposes. Philadelphia, PA: American Society for Testing and Materials. 1988.