อ้างอิง ของ บุลล์แมสติฟฟ์

    • Cunliffe, Juliette (2004). The Encyclopedia of Dog Breeds. Parragon Publishing. ISBN.
    • Fogle, Bruce (2000). The New Encyclopedia of the Dog. Dorling Kindersley (DK). ISBN.
    • McCormick, Marla. "Buster Alert".
    • Renna, Christine Hartnagle (2000). Herding Dogs: Selection and Training the Working Farm Dog. Kennel Club Books. ISBN 978-1-59378-737-0.