Howard E. Winklevoss, Alwyn V. Powell in collaboration with David L. Cohen, Ann Trueblood-RaperPublished for the Pension Research Council, Wharton School, University of Pennsylvania by R.D. Irwin1984
Dan M. McGill in collaboration with Donald S. Grubbs, JrPublished for the Pension Research Council, Wharton School, University of Pennsylvania by R.D. Irwin1984
Dan M. McGill in collaboration with Donald S. Grubbs, JrPublished for the Pension Research Council, Wharton School, University of Pennsylvania by R. D. Irwinc1979