I am wholly unfamiliar with Fr. Victor J. Pospishil. Is he an SJ?
I am familiar with Fr. Robert Taft, SJ, who was a modernist Byzantine academic.
Fr. Adrian Fortescue was an orientalist. As he is a good source with which to begin a study of the Roman liturgy, so too is hd a good soyrce to begin a study of the Eastern Churches and liturgies.
Thank you for the responses, I appreciate it. Here is the wiki page on Fr. Pospishil:
https://en.wikipedia.org/wiki/Victor_J._PospishilI saw a book by him referenced here in an older thread, which I cannot find now, about the Eastern Churches. Looked him up and read about his views on divorce which made me wary.
I actually ordered Fr. Fortescue's Study of the Roman Rite yesterday after reading your recommendation in another thread, so I will begin there (It will probably be a couple years before I can move on to studying the Eastern Churches, I'm a very slow learner

)