Barbara's Enka Site - http://www.quixium.com/enka/ Detailed description of the genre, profiles of performers, album reviews, audio samples, and links.
Enka - Song of Sweet Resignation - http://www.okada.de/archive-japanasitis/enka/enka.html Describes the origins of enka and its cultural underpinnings.
The Native Ballad, or Enka - http://web-japan.org/factsheet/music/enka.html Brief history of the music tradition.
