Studying the power elite : fifty years of who rules America? / G. William Domhoff, John L. Campbell, Ronald W. Cox, Richard W. Lachmann, Clarence Y.H. Lo, Beth Mintz, Joseph G. Peschek, Robert J.S. Ross, Daniel J. Schneider, Michael Schwartz, Kathleen C. Schwartzman, Judith Stepan-Norris