Optimal Preemptive Scheduling of Two Unrelated Processors, (with E. L. Lawler and S. Sahni), ORSA Journal on Computing, Vol. 2, No. 3, 1990, pp. 219 -- 224.

Unit Execution Time Shop Problems, Mathematics of Operations Research, Vol. 7, No. 1, February 1982, pp. 57 -- 66.

Flowshop and Jobshop Schedules: Complexity and Approximation, (with S. Sahni), Operations Research, Vol. 26, No. 1, January--February 1978, pp. 36 -- 52.