I find it difficult to know what to recommend here, as I found Magoun very dense and hardgoing, but I quite enjoyed Sutherland’s books The Cranial Bowl and Teachings in the Science of Osteopathy, and in the interest and value in hearing it from the horse’s mouth I think they are important and worthwhile to read if you want to know where this treatment originated.
There is an excellent piece by Evelyn Skinner and John McPartland on the Biodynamic Model of Osteopathy in the Cranial Field. That will take you to the journal, but I don’t think there is free acess. I have a download of it, but unfortunately don’t know how to link to the download. I found it on the Biodynamics closed Facebook group.
Research paper: Thanks to Jerry Draper-Rodi who alerted me to this. OK it’s in French, and OK it is conducted by physios, and I think it is very skeptical, but here is a very comprehensive recent French study.
Traditional Osteopathic Studies sell CDs which will give you some experience of the biodynamic model.