
1) Epic poetry 2) Medieval legend 3) Medieval poetry 
Found on 
https://www.crosswordclues.com/clue/bylina

 Bylina or Bylyna (были́на; pl. были́ны Byliny; билина Bylyna; pl. били́ни Bylyny) is a traditional East Slavic oral epic narrative poem. Byliny singers loosely utilize historical fact greatly embellished with fantasy or hyperbole to create their songs. The word Bylina is derived from the past tense of the verb `to be
Found on 
http://en.wikipedia.org/wiki/Bylina

traditional form of Old Russian and Russian heroic narrative poetry transmitted orally, still a creative tradition in the 20th century. The oldest ... [2 related articles]
Found on 
http://www.britannica.com/eb/a-z/b/137
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