Some of Filitti's biographical work was dedicated to the 16th-century Wallachian hero Michael the Brave. In 1931, he published an investigation of Michael's early career as titular Ban of Oltenia. A year later, he detailed Michael's introduction of serfdom in Wallachia: "Despre "legătura" lui Mihai Viteazul" ("On 'Bondage' under Michael the Brave"). Between these, the academic review "Analele Economice și Statistice", Vol. XIV, reissued the 1857 count of emancipated Romani slaves, annotated by Filitti. In 1932, returning to the history of Oltenian Bans, he gave an account on the Craiovești family history, taken up by "Arhivele Olteniei" journal. His ongoing research into social issues of the early 19th century produced another book, "Frământări politice și sociale în Principatele române de la 1821 la 1828" ("Political and Social Turmoil in the Romanian Principalities from 1821 to 1828", Cartea Românească, 1932). It has been described as a "non-partisan analysis" of the Wallachian uprising of 1821 and its reverberations, and features detail on the property dispute between local Orthodox monks and their Greek Orthodox competitors.