Campell, NA., J.B. Reece, L.A. Urry, M.L. Cain, S.A. Wasserman, P.V. Minorsky, & R.B. Jackson. 2008. Biology, Eighth Edition. Pearson Education, Incorporated, San Fransisco, California, USA.

Freckmann, R.W. 2010. (On-line), Robert W. Freckmann Herbarium:University of Stevens-Point. <>. Accessed 10 April 2010.

Gardner, C.A.  1981.  Wildflowers of Western Australia.  St. George Books, Perth, Western Australia.

Harris, M.  2003.  Botanica: North America.  HarperCollins Publisher, Incorporated, New York, New York, USA.

Heywood, VH.  1985. Flowering Plants of the World.  Prentice Halls, Incorporated, Englewood Cliffs, New Jersey, USA.

Hilty, J. 2010. Common Blue Violet, Viola sororia: Violet family, Violaceae. (On-line), Illinois Wildflowers. <>. Accessed 18 April 2010.

ITIS Report. 2010. Viola sororia Willd. (On-line), ITS Report. <>. Accessed 23 March 2010.

Johnson, LB., &   C.B. Lees.   1988.  Wildflowers Across America.  Cross River Press, Ltd., New York, New York, USA.

Mitchell, W.C. 2005. The New Jersey State Flower, Viola sororia Willd. (On-line), William C. Mitchell, Ph.D. <>. Accessed 16 April 2010.

NETSTATE. 2010. (On-line), NESTATE.

<>.  Accessed 20 April 2010.

Sanders, J. 2003.  The Secrets of Wildflowers. The Globe Pequot Press, Guildford, Connecticut, USA.

Teneglia, Dan. 2007. Viola papilionacea, Pursh-Rydberg. (On-line), <>. Accessed 1 April 2010.

USDA-NRCS. 2010. Plants Profile: Viola sororia. (On-line), United States of Agriculture Natural   Resources Conservation Services.

<>. Accessed 16 March 2010.


Virginia Tech. 2010. Common Blue Violet, Viola papilionacea. (On-line), Virginia Tech Identification Guide. <>. Accessed 16 March 2010.