COWSIK, R. C.; NORI, M. V. On the Fibres of Blowing Up. The Journal of the Indian Mathematical Society, [S. l.], v. 40, n. 1-4, p. 217–222, 1976. Disponível em: http://informaticsjournals.com/index.php/jims/article/view/16627. Acesso em: 4 may. 2024.