McDougald, John and Carol. (1990). History and Guide to North American Glass Pintype Insulators. 2 volumes. Loaded with the history of glass companies that made insulator. Volume 1 has 180 pages. Volume 2 has 326 pages. $40 postpaid. Volume 1 has extra pages showing glass colors in color. Volume 2 has a listing of all known North American glass insulators known at the time along with pictures. $40 postpaid via check, money order, or PayPal friends & family to Com574@clcillinois.edu. Rick Soller, 4086 Blackstone Ave., Gurnee, IL 60031.