His The favorite songs in the comic opera, Gl'uccellatori, 1775?
His 6 concerti op. 1, 1997? notes (Pietro Alessandro Gugliemi)
La morte di Cleopatra (1796). Overtura, c2009 t.p. and cover, p. [2] (Alessandro Pietro Guglielmi) editor's note and caption (Pietro Alessandro Guglielmi)
Grove music online, November 23, 2015 (under: Guglielmi: Pietro [Pier, Piero] Alessandro Guglielmi; born December 9, 1728, Massa, died November 19, 1804, Rome; composer; one of the most important figures in late 18th-century opera)