1. J.R. Van Wazer, Phosphorus and its Compounds, vol. 1, Interscience, New York, 1958
2. Y. Abe, in: Topics in Phosphorus Chemistry, vol. 11, Wiley, New York, 1983, pp. 19–67
3. B.J. Allan, B.V. Hiremath (Eds.), Solid State Optical Materials in Ceramic Transitions, vol. 28, American Ceramic Society, Westerville, OH, 1992
4. C.J. Quinn, P.D. Frayer, G.H. Beall, in: J.C. Salamone (Ed.), Polymeric Materials Encyclopedia, vol. 4, CRC, Boca Raton, FL, 1996, p. 2766