Humberto Sossa Azuela, Juan; Rubio Espino, Elsa; Santiago, Raúl; López, Alejandro; Peña Ayala, Alejandro; Cuevas Jimenez, Erik V.: 'Alternative formulations to compute the binary shape Euler number', IET Computer Vision, 2014, 8, (3), p. 171-181, DOI: 10.1049/iet-cvi.2013.0076
IET Digital Library, https://digital-library.theiet.org/;jsessionid=2an2e1mojkhmn.x-iet-live-01content/journals/10.1049/iet-cvi.2013.0076