Balibrea F, Cánovas Peña JS, López VJ. Some invariants for σ-permutation maps. Ann. Math. Sil. [Internet]. 1999 Sep. 30 [cited 2025 May 7];13:51-60. Available from: https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/14136