See all Bulgaria stamps in the StampWorld free online catalogue.
Scanned album pages from the worldwide stamp collection of Antonius Ra.
A philatelic journey through the history of Bulgaria, providing a brief summary of the most important aspects of Bulgarian history up to 1946, illustrated with stamps and maps.
Wikipedia listing of people depicted on the stamps of Bulgaria, with links to biographical data.
The splendid website of Ivan Shishkov, a stamp collector from Bulgaria. The site is designed to present detailed information for recent Bulgarian stamps.