1. B. Petrof, in: Bureau of Mines Minerals Yearbook - 1972 (US Government Printing Office, Washington, DC) pp. 97–99.
2. the Growth of Single Crystals;Laudise,1970
3. Proc. 29th Annual Symp. on Frequency Control;Barns,1975
4. Production and perfection of “z-face” quartz