WICKHAM, Hadley. Reshaping Data with the reshape Package. Journal of Statistical Software, [S. l.], v. 21, n. 12, p. 1–20, 2007. DOI: 10.18637/jss.v021.i12. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v021i12. Acesso em: 1 apr. 2025.