This is a link to the book Shyness & Love, by Dr. Brian G. Gilmartin which I found on the love-shy forum on this page: http://www.love-shy.com/resources#shynessandlovehttp://www.love-shy.com/gilmartin_book/download.php?downloadbook=true
This downloads a scanned version of the book which is 736 pages, as a .pdf file.
Still reading the book which was scanned with the permission of the author as it's out of print. Not sure if it's any good or not, but some information should be useful. This comes from 1987 so it's a little out of date.