A SUBCLASS OF δ − VALENT FUNCTIONS FOR OPERATORS ON A HILBERT SPACE. The Journals of the Nigerian Association of Mathematical Physics, [S. l.], v. 63, p. 39 –44, 2022. Disponível em: https://nampjournals.org.ng/index.php/home/article/view/108.. Acesso em: 22 dec. 2024.