In 1981, Zemskov defended his candidate's thesis "Contribution by working class to strengthening the material-technical base of agriculture in the USSR in the 1960s". In 1989, he joined the commission of the History Department of the USSR Academy of Sciences led by its corresponding member Yuri Polyakov to determine population losses and received access to statistical reports made by the OGPU-NKVD-MGB-MVD and kept in the Central State Archive of the October Revolution renamed the State Archive of the Russian Federation. According to Leonid Lopatnikov, Zemskov was the only historian admitted to the archives for the reports, and later the archives were again "closed." Between 1990 and 1992, he published the first precise statistical data on the Gulag which were based on the Gulag archives. However, his papers were criticized by Sergei Maksudov. In Maksudov's opinion, Lev Razgon and his followers including Aleksandr Solzhenitsyn did not envisage the total number of the camps very well and markedly exaggerated their size. At the same time, from their experience, they knew something extraordinarily important about the Archipelago, its diabolical anti-human nature. On the other hand, Viktor Zemskov, who published many documents by the NKVD and KGB, is very far from understanding of the Gulag essence and the nature of socio-political processes in the country. Without distinguishing the degree of accuracy and reliability of certain figures, without making a critical analysis of sources, without comparing new data with already known information, Zemskov absolutizes the published materials by presenting them as the ultimate truth. As a result, his attempts to make generalized statements with reference to a particular document, as a rule, do not hold water. In response, Zemskov wrote that the charge that Zemskov allegedly did not compare new data with already known information could not be called fair. In his words, the trouble with most western writers is that they do not benefit from such comparisons. Zemskov added that when he tried not to overuse the juxtaposition of new information with "old" one, it was only because of a sense of delicacy, not to once again psychologically traumatize the researchers whose works used incorrect figures, as it turned out after the publication of the statistics by the OGPU-NKVD-MGB-MVD. In 2005, Zemskov defended his doctoral thesis "Special settlers in the USSR. 1930–1960".
Publications
// Социологические исследования. 1991. No. 7. С. 3–16.
// Социологические исследования. 1991. No. 6. С. 10–27.
// Мир России. 1999. Т. VIII. No. 4. С. 114–124.
// Социологические исследования. 1995. No. 9. С. 118–127.
// Социологические исследования. 1991. No. 2. С. 74–75.
// Социологические исследования. 1995. No. 6. С. 3–13.
// Социологические исследования. May 1995. No. 5. С. 3–13.
// Социологические исследования. 1991. No. 4. С. 3–24.
// Социологические исследования. 1990. No. 11. С. 3–17.
// Социологические исследования. 1992. No. 8. С. 18–37.
// Социологические исследования. 1992. No. 2. С. 3–26.
