 Technological advances during the 20th century allowed cheaper production of books, resulting in a significant rise in production of popular literature and trivial literature, comparable to the similar developments in music.The division of "popular literature" and "high literature" in the 20th century is by no means absolute, and various genres such as detectives or science fiction fluctuate between the two.Largely ignored by mainstream literary criticism for the most of the century, these genres developed their own establishments and critical awards; these include the Nebula Award (since 1965), the British Fantasy Award (since 1971) or the Mythopoeic Awards (since 1971).