Complex sentence: It's adapted by Leslie Bricusse from the novel series by Hugh Lofting, primarily "The Voyages of Doctor Dolittle", "The Story of Doctor Dolittle", and "Doctor Dolittle's Circus".
Split into simpler sentences: It's adapted by Leslie Bricusse from the novel series by Hugh Lofting. It primarily fuses three of the books "The Story of Dr. Dolittle", "The Voyages of Dr. Dolittle", and "Dr. Dolittle's Circus".