Smith, L.W. 1917, Studies of North America Plecoptera (Pteronarcinae and Perlodini). Trans. Am. Entomol. Soc. 43: 433-489. Available online here.

Stark, B.P., Szczytko, S.W., and Nelson, C.R., American Stoneflies: A Photographic Guide to the Plecoptera; The Caddis Press, Columbus, Ohio. Written by three stonefly experts, this book presents a photographic overview of the Order Plecoptera. This book has more color photographs than all the other books in print that I know of. Its target audience is flyfishermen who are interested in plecoptera and what they really look like. It is available for $50 from The Caddis Press. Contact the publisher, Brian J. Armitage, at barmitag at columbus dot rr dot com, or PO Box 21039, Columbus, Ohio 43221-0039. He also publishes three other books on plecoptera and is an expert on caddisflies himself.

Stewart, K.W. and Stark, B.P., Nymphs of North American Stonefly Genera, Second Edition; The Caddis Press, Columbus, Ohio. This is a great book and a must-have for any plecoptera enthusiast. They are still in print and available for $75 from The Caddis Press. Contact the publisher, Brian J. Armitage, at barmitag at columbus dot rr dot com, or PO Box 21039, Columbus, Ohio 43221-0039. He also publishes three other books on plecoptera and is an expert on caddisflies himself.