To be honest, I don't know. I collect these photos as I surf in my free time and once I find a site, I generally take the best hair shots and move on. I have been doing this for years. Some of my photos are still on floppys! Some of the photos I share could be years old and I no longer no where I sourced them. I know that is not the answer you wanted, but that is the truth.
I like to share a little of what I have with like-minded folks like you, but there is a limit to my time these days.
Take care.