Cox, Palmer. "The Brownies Foot Race." The R. F. Outcault Society's Yellow Kid Site. 1893. 10 Dec. 2003 <http://www.neponset.com/yellowkid/>.

Notes from the Site:
"This is a very rare card signed by Palmer Cox and copyrighted 1893 by L. Prang & Company, Boston, USA. Unfortunately it has obvious writing on the obverse and was sent through the mail and postmarked February 4, 1904, even though there is some question as to whether or not it was actually issued as a postcard. This is a very choice Brownies collectible. This card is priced at $100."