N. Ivanchev

Electrically induced optical activity in the centrosymmetric crystal NaBi(MoO4)2

E. Dudnik, M. Kostov, N. Ivanchev, 1979 .

Experimental study of electrogyration in the centrosymmetric crystals Pb5GeO4(VO4)2 and Pb5SiO4(VO4)2

M. Kostov, E. Kostova, N. Ivanchev, 1981 .