See this legally free ebook:
- The Pope of Rome and the Popes of the Oriental Orthodox Church: An Essay on Monarchy in the Church, with Special Reference to Russia, from Original Documents, Russian and Greek, 2nd edition, by Rev. Caesarius Tondini (London: R. Washbourne, 1875). With Imprimatur. Available in various formats at Internet Archive and Open Library.
On the Feast of St. John Chrysostom, Archbishop of Constantinople, in the Eastern Catholic churches. For other legally free ebooks, you may access the List of Free eBooks (Arranged by Title) and the List of Free eBooks (Grouped by Subject). Blessed be God in His angels and in His saints!