From time to time prominent people in the industry will produce an in depth documentary series on a certain industry related topic. These documentaries are usually distributed via email to people that have registered to receive them during their first free showing. Once the series has shown, they can often be purchased for download.
I have watched a number of these and found them a valuable resource during my ongoing research. I have listed some of them below as a means of introduction. Should you be interested, I’m sure there is a way you can figure out how to get access to them.