References
- Dambekalne , M. , Sternberg , A. , Antonova , M. and Brante , I. 1986 . Ferroelectrics , 69 : 21
- Dambekalne , M. , Brante , I. and Sternberg , A. 1989 . Ferroelectrics , 90 : 1
- Tomashpolsky , J. , Zubova , E. , Burdina , K. and Venevtsev , J. 1968 . Crystallography , 6 : 987 in Russian