Gripenberg.
Source: Finland reveals her secret documents on Soviet policy, March 1940—June 1941. Doc. nr. 43. Wilfred Funk, New York 1941.
The book is a verbatim translation of the "Blue-White Book" published by the Foreign Ministry of Finland, 1941.
The contemporary Peoples' Commissariat for Foreign Affairs report on the Paasikivi-Vyshinski discussion (in Russian).
Finland in the Soviet foreign policy 1939-1940