“EM ALGORITHM FOR MAXIMUM LIKELIHOOD ESTIMATION OF CORRELATED PROBIT MODEL FOR TWO LONGITUDINAL ORDINAL OUTCOMES”. Annual of Sofia University St. Kliment Ohridski. Faculty of Mathematics and Informatics 104 (December 12, 2017): 217–232. Accessed December 14, 2025. https://annual.uni-sofia.bg/index.php/fmi/article/view/47.