There has been data ("John II Komnenos, Emperor of Byzantium: In the shadow of father and son (Publications of the Centre for Hellenic Studies, King's College London) - ISBN-13 978-1-4724-6026-4") available for this ISBN from the data sources that books-by-isbn.com uses, but not on the latest request on Tue Feb 4 21:04:08 2020, so the data displayed here has been removed .