Balibrea Gallego, Francisco, and Antonio Linero Bas. “On the Periodic Structure of the Antitriangular Maps on the Unit Square”. Annales Mathematicae Silesianae 13 (September 30, 1999): 39–49. Accessed May 7, 2025. https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/14135.