References on salt production
The single best source for quality information on salt production is the series of proceedings of International Salt Symposia co-sponsored by the Salt Institute going back to 1966.
For those interested in overviews and summaries, the following offer great choices:
"Salt Mines " -- one of the "Modern Marvels" series on The History Channel.
"Salt " -- another of the "Modern Marvels" series on The History Channel (release: December 2008)
"Salt " -- one of the "How Stuff Works" series on The Discovery Channel (release: January 2009)
"Salt of the Earth " -- Smithsonian Magazine (release: 1999)
"Production " -- MR BLOCH ARCHIVE
"Production " -- Salt Association (UK)