Upon his return he wrote a history of his embassy, which has survived only in a condensed version form attributed to Photios I of Constantinople. This claims that his father, Abraham, had been an ambassador to the Arabs and that his uncle, also Nonnosus, was sent on an embassy by Anastasius I.
Karl Otfried Müller, Theodor Müller, Letronne (Antoine-Jean, M.) (eds.): Fragmenta historicorum graecorum, Volume 4. (Paris, 1860), preserves the original Greek text and gives a Latin translation. It may be accessed online here