Daffy Duck's impersonation is based on Danny Kaye, probably parodying his "Tchaikovsky and Other Russians" routine.
Celebrities lampooned include Harry James, Frank Sinatra, Tommy Dorsey, Gene Krupa, Benny Goodman, W.C. Fields, Bob Burns, Margaret O'Brien, and Jimmy Durante.
When the original title sequence was lost and replaced with the standard "Blue Ribbon" substitute title card, the title was spelled "Book Review", spoiling the pun. The original was found many years later and restored on the "Looney Tunes Golden Collection: Vol. 2" DVD box set.
"So round, so firm, so fully packed..." was a slogan used by Lucky Strike cigarettes.