Research and development report. 37. Computer applications in underground mining systems: sec. 1, CONTUR program, sec. 2, RESERV-COAL program, sec. 3, RAMPLAN 1 program, sec. 4, COST-SCHED 2 program, sec. 5, ECONOVAL program, period of performance, Sept. 1968-Dec. 1973, final report [with lists of references].