MATHIAS, A.; GROND, F.; GUARDANS, R.; SEESE, D.; CANELA, M.; DIEBNER, H. H. Algorithms for Spectral Analysis of Irregularly Sampled Time Series. Journal of Statistical Software, [S. l.], v. 11, n. 2, p. 1–27, 2004. DOI: 10.18637/jss.v011.i02. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v011i02. Acesso em: 30 nov. 2021.