Horn, David; Shepherd, John (2012). Continuum Encyclopedia of Popular Music of the World. 8 – Genres: North America. Continuum. p. 438. ISBN978-1-441-16078-2. "This appeal also applied to country rock acts such as The Eagles and Ronstadt"
Stacey, Lee; Henderson, Lol, eds (2013). “Evolution of folk rock”. Encyclopedia of Music in the 20th Century. Routledge. p. 1586. ISBN978-1-57958-079-7
Smith, Chris (2006). The Greenwood Encyclopedia of Rock History: From Arenas to the Underground, 1974–1980. Greenwood Press. p. 88. ISBN0-313-32937-0. "As a result, soft-rock acts like the Eagles, the Bee Gees, Fleetwood Mac, and Elton John became some of the most popular musical artists of the decade."
