KEITH, William J. The part-frequency matrices of a partition. Journal of Algebra Combinatorics Discrete Structures and Applications, [S. l.], v. 3, n. 3, p. 177–186, 2016. Disponível em: https://jacodesmath.com/index.php/jacodesmath/article/view/46. Acesso em: 12 sep. 2026.