David Abulafia (1995). The French descent into Renaissance Italy, 1494-95: antecedents and effects. Aldershot, UK: Variorum. p. 154. ISBN978-0-86078-550-7. Cardinal Rodrigo Borgia was made guardian of d'Estouteville's sons in his Testament: Gill (2001), p. 347 note 1. Girolamo married Isabella Orsini in 1483; he was lord of Nemi, Genzano and Frascati and Count of Sarno in the Kingdom of Naples; he died c. 1495.
Westfall, Carroll William (1974). "Alberti and the Vatican Palace Type". Journal of the Society of Architectural Historians. 33 (2): 101–121, at pp. 102-103. doi:10.2307/988904. JSTOR988904.
Katherine, Walsh (1974). "The Beginnings of a National Protectorate: Curial Cardinals and the Irish Church in theFifteenth Century". Archivium Hibernicum. 32: 72–80, at p. 73. doi:10.2307/25529601. JSTOR25529601.
Westfall, Carroll William (1974). "Alberti and the Vatican Palace Type". Journal of the Society of Architectural Historians. 33 (2): 101–121, at pp. 102-103. doi:10.2307/988904. JSTOR988904.
Katherine, Walsh (1974). "The Beginnings of a National Protectorate: Curial Cardinals and the Irish Church in theFifteenth Century". Archivium Hibernicum. 32: 72–80, at p. 73. doi:10.2307/25529601. JSTOR25529601.
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Esposito, Anna (1993). Estouteville, Guillaume d', Dizionario Biografico degli Italiani, Volume 43. Retrieved: 2016-11-25.