Please, use automatic translate via yandex or google. Or try to learn russian language.
This message contains information about orthodox ierey (greek Ἱερεύς) and Volga Bulgaria, which was muslim state in the heart of Russia.
About bulgars you can read on English:
http://www.bulgars.ru/english.htm
on Turkish:
http://www.bulgars.ru/tr/vbmm.htm
on Russian:
http://bulgar-portal.ru/