1. R. S. Amirkhanov, K. I. Churyumov, and D. I. Gorodetskii, “Physical parameters of the neutral coma of comet Kohoutek (1973 XII),” Probl. Kosm. Fiz., No. 14, 89–92 (1979).
2. V. L. Afanas’ev, “Physical characteristics of the neutral coma of comet Abe, 1970g,” Probl. Kosm. Fiz., No. 9, 120–129 (1974).
3. G. A. Korn and T. M. Korn, Mathematical Handbook for Scientists and Engineers (McGraw-Hill, New York, 1968; Nauka, Moscow, 1977).
4. F. I. Kravtsov, Surface Photometry and Physical Conditions in the Head of Comet Kobayashi-Berger-Milon, 1975 IX, Available from UkrNIINTI, No. 41–Uk-88 (Kiev, 1988) [in Russian].
5. F. I. Kravtsov and I. V. Luk’yanik, “Determination of the physical parameters of gas in the neutral atmospheres of comets: The circular aperture method,” Kinematics Phys. Celestial Bodies 29, 285–290 (2013).