

Source: Voogt, G. D. (1907). Our domestic animals, their habits, intelligence and usefulness. Boston, Massachusetts: Ginn & Co.





From Dogdom, January 1910

Mason, W. E. (1915). Dogs of all nations. [S.l., s.n.]

Source: Anon. (1919, March). The sagacity and courage of dogs. The National Geographic Magazine, pp. 253-274

Rogers, A. L. (1922). Cairn and Sealyham terriers. New York, NY: R. M. McBride & Company


Source: Ash, E. C. (1927). Dogs: their history and development, volume II. Boston, Massachusetts: Houghton Mifflin Company
