Lettres des souverains portugais à Charles Quint et à l'Impératrice, 1528-1532, 1994: t.p. (l'Impératrice) p. 13 (l'Impératrice D. Isabel de Portugal; sister of João III of Portugal; wife of Carlos V, Holy Roman Emperor, King of Spain)

Verbo encic. luso-bras. de cultura, 1963 (hdg.: Isabel--Infanta de Portugal, rainha de Espanha, imperatriz da Alemanha; b. 10-24-1503, in Lisbon; d. 05-01-1539, in Toledo, Spain; frequently Regente of Spain in her husbands absences)

Encic. univ. ilust., c1926 (hdg.: Isabel; Reina de España y emperatriz de Alemania [Holy Roman Empire]; 1503-1539; in 1526 she married her cousin, Carlos V of Spain; 3 captions on same page: Isabel de Portugal)

Story of the Emperor Charles V and the Infanta Isabella, [19--]: t.p. (Infanta Isabella)