Don't know if this will be any good to you, Jeff (it should, though), as it's not specifically on spectroscopy, but here's a book that might come in handy....
http://www.abbeys.com.au/items.asp?i...0Submillimeter
Here's another which will be of interest....
http://www.abbeys.com.au/items.asp?i...0and%20Spectra