November 7 1991
Marquard, Robert D.
May 31 1991
Ren, Gao
April 8 1991
Donnelly, Gerard T.
March 4 1991
October 15 1991
Schmidt Barkley, Jan
May 28 1991
Ware, George
October 4 1991
May 29 1991
Cheng Lin, Zhang
March 8 1991
circa 1991
August 20 1991
October 21 1991
Qingru, Zhao , Ware, George
1991
May 9 1991
Borden, William K.
October 1 1991
Lampa, Wayne
1990s
February 22 1991
September 26 1991
Ward, Ruth
August 2 1991
Hultquist, Brett
September 5 1991
Marquardt, Barbara
June 3 1991
Herdegen, Cecilia K.
March 16 1991
September 1991
March 31 1991
August 9 1991