Here are some further reading suggestions, covering a range of interpretations:
Churchill
Andrew Roberts, Churchill: Walking with Destiny (2018)
Richard Toye, Churchill’s Empire: The World That Made Him and the World He Made (2010)
Madhusree Mukerjee, Churchill’s Secret War: The British Empire and the Ravaging of India during World War II (2013)
William Manchester, The Last Lion: Winston Spencer Churchill. (1989)
Robert Rhodes James, Churchill, A Study in Failure, 1900-1939 (1973)
Geoffrey Wheatcroft, Churchill’s Shadow: The Life and Afterlife of Winston Churchill (2021)
You can also read our blog posts that summarise the cases for and against Winston Churchill.
Stalin
Robert Tucker, Stalin in Power (1990)
Isaac Deutscher, Stalin: A Political Biography (1949)
O Figes, The Whisperers: Private Life in Stalin’s Russia (2007)
S S Montefiore Stalin, The Court of the Red Tsar (2003)
Sheila Fitzpatrick, Stalin’s Peasants (1994)
Sheila Fitzpatrick, Education and Social Mobility in the Soviet Union 1921-1934 (1979)
D. Filtzer, Soviet Workers and Stalinist Industrialization (1986)
Stephen Kotkin, Magnetic Mountain (1995)
You can also read our blog posts offering a range of perspectives on Stalin, here and here.