El Mokadem and the other authors were all colleagues of Warfield's working at Battelle Memorial Institute. The conference was in Phoenix on 20-22 Nov. 1974. Warfield says he did not go to this particular conference, that Ahmed El Mokadem probably was the chief presenter of the conference paper because he did most of the work. El-Mokadem's paper was reprinted in the book PORTRAITS OF COMPLEXITY which is available from Fenwick Library, George Mason University, and also from Library of Congress, Washington, D.C., using call number H61 .P589. A paper offprint of full text of the article is at Fenwick Library, Box 16/30, C0016, SCRC, George Mason University Libraries. FULL CITATION OF THE REPRINT VERSION: Reprinted as Chapter 20 in M. Baldwin, ed., Portraits of Complexity, Battelle Monograph #9 (Columbus, OH: Battelle, 1975) 194-201.