Analysis of information sources in references of the Wikipedia article "Πραξικόπημα του Μαΐου (Πολωνία)" in Greek language version.
The Archives of Modern Records in Warsaw, Prezydium Rady Ministrow, catalogue no. 33, p. 330.
The Archives of Modern Records in Warsaw, Prezydium Rady Ministrow, catalogue no. 33, p. 330.