In April 1880, Markov defended his master's thesis "About Binary Quadratic Forms with Positive Determinant", which was encouraged by Aleksandr Korkin and Yegor Zolotarev. Source: Internet
In November 1991 Yeltsin appointed a new government, with himself as acting prime minister, a post he held until the appointment of Yegor Gaidar as acting prime minister in June 1992. Source: Internet