A New Class of Gradient Estimators for Queueing Systems with Real-Time Constraints

[C37]Gong, W-B., Cassandras, C.G., Kallmes, M.H., and Wardi, Y.,
A New Class of Gradient Estimators for Queueing Systems with Real-Time Constraints Proc. 29th IEEE Conf. Decision and Control , pp. 891-896, December   1990.