What is the difference between Greco-Roman biography and ancient Greek historiography? Where would one start to find sources?
Maybe try your Logos search? You have a sizable library. All 3 search terms are sufficiently specific.
start with Greco-Roman Historiography - Biblical Studies - Oxford Bibliographies and Greek Historiography - Classics - Oxford Bibliographies or even Bart D. Ehrman: Defining “Greco-Roman Biography” – The Amateur Exegete
