Brower, Lincoln (Sweet Briar Coll. Sweet Briar, VA, United States)
Taylor, Orley R. (Kansas Univ. Lawrence, KS, United States)
Williams, Ernest H. (Hamilton Coll. Clinton, NY, United States)
Slayback, Daniel (Science Systems and Applications, Inc. Greenbelt, MD, United States)
Zubieta, Raul R. (Universidad Nacional Autonoma de Mexico Coyoacan, Mexico)
Ramirez, M. Isabel (Universidad Nacional Autonoma de Mexico Morelia, Mexico)