Observation of two-electron exchange between tin centers in solid Pb1 - xSnxSe solutions Nasredinov, F. S. ; Prokof'eva, L. V. ; Zarubo, S. V. ; Kurmantaev, A. N. ; Seregin, P. P. Abstract Publication: Soviet Journal of Experimental and Theoretical Physics Letters Pub Date: July 1983 Bibcode: 1983JETPL..38...22N