For our actual work we had used the TPO-information of several books / handouts ... ! Mostly they are represented in the list below.
Many thanks to the authors for their great work !!

Main sources for our actual work :

  1. Die Bezeichnung der Poststempelformen ; Hans-Joachim Anderson, Poststempelgilde e.V. Soest 1996

  2. A Magyar Belyegek Monografiaja Vol.I

  3. A Magyar Belyegek Monografiaja Vol.VI

  4. Monografie Ceskoslovenskych Znamek Vol. 16

  5. Vlakove Postove Spoje V Ceskoslovensku 1938-1945 ( A.Tesitel , J. Tekel )

  6. The Visszatert Period in Hungarian Philately 1938-1945 ( M. Benford )

  7. Austro-Hungarian A.P.O's 1914-1918 ( K. Tramnet )