Michael and Steven A. Baur, The Beatles and Philosophy (2006)
Everything from the group's take on "reality" to their existential being and "somethingness" is reviewed in philosophical, yet readable, terms.
The Beatles, The Beatles Complete Chord Songbook (2000)
This chord book contains practically every Beatles song released.
Bob Spitz, The Beatles: The Biography (2006)
Bob Spitz painstakingly goes through the story of the Beatles in this 1,000-page biography.
Bob Spitz, Yeah! Yeah! Yeah!: The Beatles, Beatlemania, and the Music that Changed the World (2007)
This coffee-table account of the band's early years is more or less an abridged, more accessible version of author Bob Spitz's extended biography.