TORRES-PEIMBERT, S.; ARRIETA, A.; BAUTISTA, M. Echelle spectroscopy of the nuclei of the highly collimated bipolar planetary nebulae M 2-9 and M 1-91. Revista Mexicana de Astronomía y Astrofísica, [S. l.], v. 46, n. 2, 2010. Disponível em: https://journals.unam.mx/index.php/revmexaa/article/view/20569. Acesso em: 10 may. 2024.