•The Beatles. Official Website. Available at: https://www.thebeatles.com

•Davies, Hunter. The Beatles: The Authorised Biography. London: Heinemann, 1968.

•MacDonald, Ian. Revolution in the Head: The Beatles’ Records and the Sixties. London: Pimlico, 1994.

•Lewisohn, Mark. The Complete Beatles Chronicle. London: Hamlyn, 1992.

•Everett, Walter. The Beatles as Musicians: Revolver through the Anthology. Oxford University Press, 1999.

•Rolling Stone Magazine. The Beatles: Biography and Legacy. Available at: https://www.rollingstone.com

•Britannica. The Beatles – British Rock Group. Encyclopaedia Britannica. Available at: https://www.britannica.com

•People Magazine. “All About the Beatles Members – Legendary Band.” Available at: https://en.wikipedia.org/wiki/Collaborations_between_ex-Beatles

•Wikipedia. Collaborations between ex-Beatles. Available at: https://people.com/all-about-the-beatles-members-legendary-band-7497753