Encyc. Brit., micropaedia, 1981 v. 1, p. 426 (John XXIII 1410-1415)
GDEL (Jean XXIII, Baldassare Cossa, b. Naples ca. 1370, d. 1419, antipope 1410-1415; deposed by Council of Constance; he later made his peace with Pope Martin V and was reaccepted into College of Cardinals)
Kings, rulers & statesmen, 1976 p. 372 (John XXIII anti-pope, b. 1370? d. 1419)
Kitts, E.J. Pope John XXIII and Master John Hus, 1910 p. 52 (Baldassare Cossa became Pope John the Twenty-Third)
LC manual cat. (hdg.: Joannes XXIII, antipope, d. 1419; info: b. ca. 1370; variants: Papas Iōannēs XXIII, Papa Ioann XXIII, Baltazar Kossa, Jan XXIII)
New Catholic encyc., 1967 v. 1, p. 632 (John XXIII 1410-1415) v. 7, p. 1020 (died 1419)