CHUVAEV, K.; OKNYANSKIJ, V. .; LYUTY, V. Optical variability of NGC 4151 during past 100 years . Известия Крымской астрофизической обсерватории, [S. l.], v. 104, n. 3, p. 109–113, 2008. Disponível em: https://jncrao.ru/index.php/izvcrao/article/view/754. Acesso em: 22 ноя. 2024.