Here you are. N. R. Woodward put it all together way back when. Sit down, grab a cool one and start reading. You will end up being a lot smarter when you finish reading either or both of these soft cover books. The history of the companies is covered and a ton of info is presented. Go ahead, show off all that new found knowledge. Bore your friends, but you'll be able to hold your own in a group of fellow insulator collectors. This great two book set is only $12 plus shipping. media mail is cheap! Sold two sets but I still have one more set and it is in good condition.