“Properties of the Maximum Likelihood Estimation of Constant Drift and Diffusion Parameters in $k$-Dimensional Diffusion Process Observed at Discrete Random Sampling”. Annual of Sofia University St. Kliment Ohridski. Faculty of Mathematics and Informatics, vol. 93, Dec. 2001, pp. 61-71, https://annual.uni-sofia.bg/index.php/fmi/article/view/204.