List of all churches in ECAV:
          The most of churches are  equipped with the organ and bells. Moreover, as a rule, they have  intersting building acoustics.
http://www.ecav.sk/archiv/dokumenty/kostoly.htm

Organ Sacred music bibliography:
http://www.music.indiana.edu/muslib/L631/projects/1999/organbib.html

Organ history:
http://www.romanliturgy.net/organ_history.html

Organ literature: A historicla survey:
http://www.organresearch.net/cvr4.html