BiirdeinyiA. G., and SvishchukA. V. “Optimal Control over Evolution Stochastic Systems and Its Application to Stochastic Models of Financial Mathematics”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 50, no. 5, May 1998, pp. 687–698, https://umj.imath.kiev.ua/index.php/umj/article/view/4907.