Ulo Sooster discussed by Eda Sepp in Estonian Non-conformist art from the Soviet occupation in 1944 to Perestroika, p. 148 in chapter 2 in Art of the Baltics: The Struggle for Freedom of Artistic Expression under the Soviets, 1945-1991, edited by Jane Voorhees, Alla Rosenfeld and Norton T. Dodge, exhibition catalog Zimmerli Art Museum, Rutgers University, New Brunswick, New Jersey, 2001/2002, ISBN978-0813530420
