1. K. A. Kalder, Tr. Inst. Fiz. Astron., Akad. Nauk Est. SSR, 42, 81–108 (1974).
2. K. A. Kalder and A. F. Malysheva, Tr. Inst. Fiz. Astron., Akad. Nauk Est. SSR, 36, 154–162 (1969).
3. K. A. Kalder, in: Single Crystals, Scintillators, and Organic Luminophores [in Russian], VNII Monokristallov, Kharkov (1969), No. 5, Part I, pp. 205–210.
4. A. B. Lyskovich, G. M. Pentsak, Z. P. Chornii, and S. K. Zherebetskii, Opt. Spektrosk., 28, No. 2, 302–306 (1970).
5. R. Hofstadter, E. W. O’Dell, and C. T. Schmidt, IEEE Trans. Nucl. Sci., 5–11, No. 3, 12–14 (1964).