Embassy of the Czech Republic in Bulgaria:

http://www.mzv.cz/sofia/en/index.html

http://old.mzv.cz/wwwo/default.asp?idj=2&amb=71

Embassy of the Slovak Republic in Bulgaria:

http://www.mzv.sk/sofia

Czechoslovak Institute for Foreign Relations:

http://www.csuz.cz/

Society of Slovaks Living Abroad :

http://www.uszz.sk/

Ministry of Foreign Affairs of the Czech Republic:

http://www.mzv.cz/jnp/en/index.html

Ministry of Foreign Affairs of the Slovak Republic:

http://www.mzv.sk/

The Official Website of the Czech Republic:

http://www.czech.cz/en?i=1

The Official Website of the Slovak Republic:

http://www.slovakia.org/official

Czech cultural centre in Sofia:

http://www.ceskicentar.cz/en/index.html

Čechopis - Magazine of theBulgarian Bohemian society:

http://cechopis.atspace.com/

Wikipedia - about Czechoslovakia

http://en.wikipedia.org/wiki/Československo

Wikipedia - about the Czech Republic

http://en.wikipedia.org/wiki/Czech_Republic

Wikipedia - about the Slovak Republic

http://en.wikipedia.org/wiki/Slovak_Republic