@unpublished{   Crowl81a,
author          = "Lawrence A. Crowl",
title           = "Processes and Process Communication
                  in the {Ada} Programming Language",
note            = "Department of Computer Science,
                  Virginia Polytechnic Institute and State University,
                  Blacksburg, Virginia, 24061-0106",
month           = "Fall",
year            = 1981 }