Universal Radio is listing two new books available on the history of
shortwave:

Broadcasting on the Short Waves, 1945 to Today
http://www.universal-radio.com/catalog/books/2549.html

Listening on the Short Waves, 1945 to Today
http://www.universal-radio.com/catalog/books/1651.html

Both are by Jerome S. Berg, whose earlier work (On the Short Waves,
1923-1945) was recommended by Joe A. a few years back in this forum
(at a time when there was a bit more shortwave discussion in
rec.radio.shortwave).