An example of Snell's refraction law for a usual wave and an extraordinary wave being polarized by vector D in a plane of incidence (xy) for certain values of a components of an electrical and magnetic tensors: (1) εxx = εyy = εzz = 4; μxx = μyy = μzz = 1; εik = 0; μik = 0; (2) εxx = εyy = εzz = 4; μxx = μyy = μzz = 2; εik = 0; μik = 1; (3) εxx = εyy = εzz = 4; μxx = μyy = μzz = 2; εik = 1; μik = 1; (4) εxx = εyy = εzz = 4; μxx = μyy = μzz = 2; εik = 1; μik = 0