Not him, but I don't like deniers desu.
Take your pick.
Adler, N., Victims of Soviet Terror, 1993 cites these:
Chistyakovoy, V. (Neva, no.10): 20 million killed during the 1930s.
Dyadkin, I.G. (Demograficheskaya statistika neyestestvennoy smertnosti v SSSR 1918-1956 ): 56 to 62 million "unnatural deaths" for the USSR overall, with 34 to 49 million under Stalin.
Gold, John.: 50-60 million.
Davies, Norman (Europe A History, 1998): c. 50 million killed 1924-53, excluding WW2 war losses. This would divide (more or less) into 33M pre-war and 17M after 1939.
Solzhenitsyn, Gulag Archipelago,
Intro to Perennial Classics Edition by Edward Ericson: Solzhenitsyn publicized an estimate of 60 million. Aleksandr Yakovlev estimates perhaps 35 million.
Page 178: citing Kurganov, 66 million lives lost between 1917 and 1959
Rummel, 1990: 61,911,000 democides in the USSR 1917-87, of which 51,755,000 occurred during the Stalin years. This divides up into:
1923-29: 2,200,000 (plus 1M non-democidal famine deaths)
1929-39: 15,785,000 (plus 2M non-democidal famine)
1939-45: 18,157,000
1946-54: 15,613,000 (plus 333,000 non-democidal famine)
TOTAL: 51,755,000 democides and 3,333,000 non-demo. famine
William Cockerham, Health and Social Change in Russia and Eastern Europe: 50M+
Wallechinsky: 13M (1930-32) + 7M (1934-38)
Cited by Wallechinsky:
Medvedev, Roy (Let History Judge): 40 million.
Solzhenitsyn, Aleksandr: 60 million.
Nove, Alec ("Victims of Stalinism: How Many?" in J. Arch Getty (ed.) Stalinist Terror: New Perspectives, 1993): 9,500,000 "surplus deaths" during the 1930s.
Cited in Nove:
Maksudov, S. (Poteri naseleniya SSSR, 1989): 9.8 million abnormal deaths between 1926 and 1937.
Tsaplin, V.V. ("Statistika zherty naseleniya v 30e gody" 1989): 6,600,000 deaths (hunger, camps and prisons) between the 1926 and 1937 censuses.
Dugin, A. ("Stalinizm: legendy i fakty" 1989): 642,980 counterrevolutionaries shot 1921-53.