Caldas, M., Jafari, S. and Latif, R.M. (2009) “? - open sets and a new class of functions”, Pro Mathematica, 23(45-46), pp. 155–174. Available at: https://revistas.pucp.edu.pe/index.php/promathematica/article/view/10270 (Accessed: 10 October 2026).