1. S. Motoi, Bull. Chem. Soc. Jpn.
7 (1992) 162.
2. M. Kajiwara, ibid.
23 (1988) 960.
3. Y. Kakamu, J. Refract. Jpn.
39 (1987) 510.
4. K. Ichikawa and N. Tsukamoto, “Zircon, Science and Technology”, edited by S. Somiya (Uchidarokakuho, Japan, 1988) pp. 224–42.
5. S. Komarneni and R. Roy, “Zircon, Science and Technology”, edited by S. Somiya (Uchidarokakuho, Japan, 1988) pp. 289–98.