Mark Lewisohn

Mark Lewisohn (born 16 June 1958) is an English historian and biographer. Since the 1980s, he has written many reference books about the Beatles and has worked for EMI, MPL Communications and Apple Corps. He has been referred to as the world's leading authority on the band. His major works include ''The Complete Beatles Recording Sessions'' (1988), a history of the group's session dates, and ''The Beatles: All These Years'' (2013–present), a three-volume series intended as the group's most comprehensive biography. Provided by Wikipedia