Nielsen Business Media, Inc., Billboard, Nielsen Business Media, Inc., , 67– (ISSN0006-2510, lire en ligne)
Joel Whitburn, Top Country Singles, 1944 to 2001 : Chart Data Compiled from Billboard's Country Singles Charts, 1944-2001, Record Research, , 591 p. (ISBN978-0-89820-151-2, lire en ligne)
issn.org
portal.issn.org
Nielsen Business Media, Inc., Billboard, Nielsen Business Media, Inc., , 67– (ISSN0006-2510, lire en ligne)