DE LEEUW, J. Server-side Statistics Scripting in PHP. Journal of Statistical Software, [S. l.], v. 2, n. 1, p. 1–13, 1997. DOI: 10.18637/jss.v002.i01. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v002i01. Acesso em: 9 aug. 2022.