The Butterflies of Canada, 1998. Layberry, R.A., P.W. Hall, J.D. Lafontaine, University of Toronto Press, Toronto.

Maritimes Butterfly Atlas - you have to dig a bit to get to the species pages, but there's some very useful information about all the species found in the Maritimes.

Le Guide des Papillons du Québec, 1999. Louis Handfield, Broquet, Ottawa.

Papillons et Chenilles du Québec et des Maritimes, 2012. Michel Leboeuf and Stéphane Le Tirant, Éditions Michel Quintin, Waterloo ( Québec ).

Checklist of Ontario Butterflies, 2012. Jones, C.D. , Hamilton Naturalists Club, Ontario Ministry of Natural Resources & Ontario Nature. ( available from The Hamilton Naturalists Club )

The ROM Field Guide to Butterflies of Ontario, 2013. Hall, P.W., C.D. Jones, A. Guidotti, B. Hubley, Royal Ontario Museum, Toronto.

A Catalogue of the Butterflies of the United States and Canada, 2008. Jonathan Pelham, The Journal of Research on the Lepidoptera, Vol. 40.

Butterflies of the East Coast: An Observer's Guide, 2005. Rick Cech and Guy Tudor, Princeton University Press, Princeton and Oxford.

Kaufman Field Guide to Butterflies of North America, 2003. Brock, J.P., K. Kaufman, Hillstar Editions, Tucson.

The Butterflies of North America: A Natural History and Field Guide, 1986. Scott, James A., Stanford University Press, Stanford, California.