Photograph of a halter class at the 1908 Southwestern Exposition and Livestock Show
Unknown author<span style="display: none;">Unknown author</span>
<i>The American Quarter Horse</i> by Steven D. Price <a href="//commons.wikimedia.org/wiki/Special:BookSources/1-55821-643-X" title="Special:BookSources/1-55821-643-X">ISBN 1-55821-643-X</a>