High temperature conductivity and F-centres in ZnSLott, Kalju; Varvas, JüriPhysica status solidi. B, Basic solid state physics1973 / [?] https://www.ester.ee/record=b1198778*est

Stability of F-centres in additively coloured ZnS crystals at low temperaturesLott, KaljuPhysica status solidi. B, Basic solid state physics1972 / K43-K44 https://www.ester.ee/record=b1198778*est