Citation: Ni. Merkulova et al., Characteristics of the continuum variability of the nucleus of NGC 4151 inthe optical from 1989-1996, ASTRON ASTR, 374(3), 2001, pp. 770-783
Citation: Ii. Pronik et al., Characteristics of the variability of the nucleus of NGC 1275 in the optical in 1982-1994, ASTRON ASTR, 351(1), 1999, pp. 21-30
Citation: Ii. Pronik et al., UBVRI observations of the nucleus of NGC 1275 from 1989 to 1994: Microvariability, ASTRONOM J, 117(5), 1999, pp. 2141-2151
Citation: Ni. Merkulova et al., Simultaneous UBVRI light curves of the Seyfert galaxy NGC 4151 during the extraordinary brightening from 1989 to 1996, ASTRONOM J, 117(5), 1999, pp. 2177-2184