ESTLAND
1919-1920
Literatuur: 1919-1920 Estland
Epstein, A. Die Kriegzensur der Postsendungen in Estland wahrend des 1e Weltkriegs. Der Estnische Philatelist. 1996, 36, p 189-198.
Ojaste, E. Osi, H. Ostrat, A. ‘S.K.’ – Postitsensuurist ja selle templitest vabadussõja ajal. Eesti Filatelist – The Estonian Philatelist. 1973, 14. p. 23-32. About: Estonian military postal censorship and markings during the independence war, article in Estonian and short English summary.
Ojaste, E. Osi, H. Ostrat, A. “S.K.”-postitsensuurist ja selle templitest vabadussoja ajal.
Eesti Filatelist – The Estonian Philatelist. 1975, 16-17, p. 107-110 (addition on the original article in EF 1973 ; 14) . About: Estonian armed forces censorship of civilin mail 1919-1920, article in Estonian, short English summary.
Ojaste, E. Postzersur und die Zensurstempel wahrend des estonischen Befreiungskrieges 1918-1920. AGZ Rundbriefe 12/ 1975. p 1-5
Ojaste, E. Osi, H. Ostrat, A.Censorship and censor marks during the Estonian War of Independence. The British Journal of Russian Philately. 1976, 53. p. 34-40.
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1939-1944
Literatuur: Estland
Erelt. P.. Postal censorship in Estonia 1939-1944. Eesti Filatelist – The Estonian Philatelist. 1998, 37. p. 69-81. About: Postal censorship: I Estonian censorship during the period of Soviet military bases 1939-1940, II Soviet censorship in Estonia 1940-1941, III German censorship mail to/from Estonia 1939-1940 and 1941-1944, IV Estonian censorship during German occupation 1941-1942, article in Estonian, English and German.
Erelt. P. Mail censoring in Estonia in 1934-1940. Eesti Filatelist – The Estonian Philatelist. 2001, 38. p. 40-67. About: censoring under Konstantin Päts in 1934-39, censoring in the period of Soviet military bases 1939-40, mail censoring after the occupation of Estonia in 1940, article in Estonian, summary in English and German.
Hurt, V. Ojaste, E. (1986) ESTONIA PHILATELY & POSTAL HISTORY HANDBOOK • CATALOGUE. https://postiajalugu.ee/eesti-estonia-philately-postal-history-handbook-catalogue-vambola-hurt-elmar-ojaste-pdf/
Ojaste, E. Estonian postal censorship during the period of Soviet Unions military bases 1939—1940. Eesti Filatelist – The Estonian Philatelist. 1984. 30. p. 216-228. About: postmarks of postal censorship, article in Eestonian with translation in English, followed (p. 229-234) by ‘Väliposti seadlus 1940 [ Estonian fieldpost law 1940], in Estonian, summary in English]