suppression of dissent was dramatically reduced and it also took new forms. The internal critics of the system were convicted of anti-Soviet agitation, anti-Soviet slander, or they were accused of being "social parasites". Other critics were accused of being mentally ill, they were accused of having sluggish schizophrenia and incarcerated in "psikhushkas", i.e. mental hospitals which were used as prisons by the Soviet authorities. A number of notable dissidents, including Aleksandr Solzhenitsyn, Vladimir Bukovsky, and Andrei Sakharov, were sent to internal or external exile. Loss of life Estimates of the number of deaths attributable to Joseph Stalin vary widely. Some scholars assert that record-keeping of the executions of political prisoners and ethnic minorities are neither reliable nor complete; others contend archival materials contain irrefutable data far superior to sources utilized prior to 1991, such as statements from emigres and other informants. Those historians working after the Soviet Union's dissolution have estimated victim totals ranging from approximately 3 million to nearly 9 million. Some scholars still assert that the death toll could be in the tens of millions. Counting the losses In 2011, the historian Timothy D. Snyder, after assessing 20 years of historical research in Eastern European archives, asserts that Stalin deliberately killed about 6 million (rising to 9 million if foreseeable deaths arising from policies are taken into account). The release of previously secret reports from the Soviet archives in the 1990s indicate that the victims of repression in the Stalin era were about 9 million persons. Some historians claim that the death toll was around 20 million based on their own demographic analysis and from dated information published before the release of the reports from the Soviet archives. American historian Richard Pipes noted: "Censuses revealed that between 1932 and 1939—that is, after collectivization but before World War II—the population decreased by 9 to 10 million people. In his most recent edition of The Great Terror (2007), Robert Conquest states that while exact numbers may never be known with complete certainty, at least 15 million people were killed "by the whole range of Soviet regime's terrors". Rudolph Rummel in 2006 said that the earlier higher victim total estimates are correct, although he includes those killed by the government of the Soviet Union in other Eastern European countries as well. Conversely, J. Arch Getty, Stephen G. Wheatcroft and others insist that the opening of the Soviet archives has vindicated the