APA

Energy resources and excavation, . (1977). Rock Mechanics. U.S. Symposium 18, held at Keystone, Colorado, June 22-24, 1977. Proceedings. Golden, CO: Colorado School of Mines Press.

Chicago

Energy resources and excavation, . 1977. Rock Mechanics. U.S. Symposium 18, held at Keystone, Colorado, June 22-24, 1977. Proceedings. Golden, CO: Colorado School of Mines Press.

Harvard

Energy resources and excavation, . (1977). Rock Mechanics. U.S. Symposium 18, held at Keystone, Colorado, June 22-24, 1977. Proceedings. Golden, CO: Colorado School of Mines Press.

MLA

Energy resources and excavation, . Rock Mechanics. U.S. Symposium 18, held at Keystone, Colorado, June 22-24, 1977. Proceedings. Golden, CO: Colorado School of Mines Press. 1977.