Amantos also published important studies on the Greeks of Asia Minor in the Middle Ages (Ὁ Ἑλληνισμός τῆς Μικράς Ἀσίας κατὰ τον μεσαίωνα, 1919), the South Slavs, Bulgarians, and Albanians (Οἱ βόρειοι γείτονες τῆς Ἑλλάδος (Βούλγαροι - Ἀλβανοί - Νοτιοσλάβοι), 1923), and a number of articles focusing particularly on the history of Slavs in Greece and the relations of the Greeks with the Serbs, Bulgarians, and Turks. He extended his attention to the Ottoman era as well, with studies on Rigas Feraios, the Phanariote official Alexandros Mavrokordatos, the Chiot Renaissance scholar Leo Allatius, and Adamantios Korais. Other works include the Brief History of Cyprus in 1956, a number of studies on the Monastery of Saint Catherine on Mount Sinai, and studies dedicated to his native Chios, particularly during the Ottoman era.