A study for a putto carrying an olive wreath in a pendentive below Bigari's cupola of Saint Peter entrusting Pope Celestino with the election of Saint Petronius as Bishop of Bologna in the Buoncompagni Chapel of the Metropolitan Church of Saint Peter, Bologna, dated 1730, C. Casali Pedrielli, Vittorio Maria Bigari, Bologna, 1991, no. 14, illustrated.
Another study for the same putto, bearing an old attribution to Carlo Maratta, is in a French private collection.
A further study of a putto, of similar size and technique, is in the Pinacoteca Nazionale, Bologna, inv. no. 1896, C. Casali Pedrielli, op. cit., no. 75, illustrated.