s, Fermilab, 1981-1983 [3] Research associate in theoretical physics, University of Wisconsin-Madison, 1979-1981 [4] Visiting appointments at IAS (Princeton) 1983; CINVESTAV (Mexico) 1985; Durham Univ (UK) 1987; OSU 1990; Yukawa Institute (Kyoto) 1994 c. Publications Five Relevant to Recent Research: [1] "B