Eastern catholic theology is a broad subject. It includes the copts, the Syrians, and the byzantines. Generally you are probably going to have to look at Orthodox books. I would suggest reading anything by Vladimir Lossky or Bishop Ware. John Meyendorff has a more historical approach that is good. For a Coptic perspective read pope shenouda’s writings. There aren’t a whole lot of books on Syriac Christianity. All I can suggest is Sebastian Brock, seely Beggiani, and some of the saints like Isaac of Nineveh and Gregory of narek. Learning the history of the divisions between the Catholic west and the orthodox east is a good approach as well.
