The main areas of his works included dialectology and accentology of South Slavic languages, as well as philologically impeccable editions of 15th to 18th century writers for the Yugoslav Academy of Sciences and Arts.

He was also engaged in the field of numismatics (Dubrovačka numizmatika, 1924-1925), inheriting the interest and coin collection from his father Pavle, the last commander in Kotor during Petar II Petrović-Njegoš's lifetime.

On the other hand, Rešetar's editions of the Renaissance and Baroque poets and playwrights are still the standard printed issues; only modern computerized textology analyses, done in the Institute for Croatian language and linguistics, have begun to question some aspects of his transliteration choices on the graphemics level.

Remote from the lines from which the greater events of history moved in the Middle Ages, the three communities have remained singularly conservative of ancestral type in habit and speech.

Even at the present they lie remote from the travel routes and scarcely touched by the modern life of Italy save in so far as the Government reaches out to them hands collecting taxes and drawing their youth into military service.