ROUSSEAU, R.; THELWALL, M. Escher Staircases on the World Wide Web. First Monday, [S. l.], v. 9, n. 6, 2004. DOI: 10.5210/fm.v9i6.1152. Disponível em: https://firstmonday.org/ojs/index.php/fm/article/view/1152. Acesso em: 25 jan. 2022.