Thomas MacFarlane (Ph.D., Music Composition, 2005) recently published a book The Abbey Road Medley: Extended Forms in Popular Music with Scarecrow Press/Rowman & Littlefield Publishing Group. He developed his doctoral dissertation into this book length study of the impact of recording technology on the compositional style of the Beatles. A detailed description of the book and ordering information from the publisher is available here.
Dr. MacFarlane has also written an article entitled, 'Sgt. Pepper's Quest For Extended Form' for The International Association for the Study of Popular Music, as part of a journal commemorating the 40th anniversary of the release of 'Sgt. Pepper's Lonely Hearts Club Band'. The journal issue is entitled 'Sgt. Pepper and the Beatles: It Was Forty Years Ago Today' Aldershot Ashgate [ISBN 978 0 7546 6249 5], and is being edited by Oliver Julien from the University of Paris-Sorbonne (Paris IV). It is scheduled to appear in 2008.