Georgiev, S., J. Morais, and W. Spross. “New Aspects on Elementary Functions in the Context of Quaternionic Analysis”. CUBO, A Mathematical Journal 14, no. 1 (March 1, 2012): 93–110. Accessed January 30, 2026. https://cubo.ufro.cl/index.php/cubo/article/view/1356.