Ney, Andrei. “Structures algébriques à élément Fixe Qui modélisent De Divers phénomènes: Fixed-Element Algebraic Structures That Model Various Phenomena”. Rev. Anal. Numér. Théor. Approx. 26, no. 1 (August 1, 1997): 165–177. Accessed December 4, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1997-vol26-nos1-2-art22.