Doris De Montreville: Fourth Book of Junior Authors & Illustrators. H. W. Wilson Company, 1978, ISBN 978-0-8242-0568-3, S.133 (google.de).
Charles Baile de Laperrière: Who’s Who in Art: Biographies of Leading Men and Women in the World of Art Today-Artists, Designers, Craftsmen, Critics, Writers, Teachers and Curators, With an Appendi. Hilmarton Manor Press, 2004, ISBN 978-0-904722-39-0, S.254 (google.de).
Jennifer Warner: The Unofficial History of the Paddington Bear. BookCaps Study Guides, 2014, ISBN 978-1-62917-381-8, S.16f. (google.de).