Galbreath, Donald Lindsay (13 September 1930). "A Treatise on Ecclesiastical Heraldry". W. Heffer and sons, Limited. Archived from the original on 10 March 2024. Retrieved 12 November 2020 – via Google Books.
"Holy See, The country brief". Department of Foreign Affairs and Trade (Government of Australia). Archived from the original on 20 February 2024. Retrieved 20 February 2024.
United States. Department of State. Bureau of Public Affairs (1989). "The Holy See". Backgr Notes Ser: 1–4. PMID12178005. Archived from the original on 23 January 2023. Retrieved 28 August 2023.
"Holy See, The country brief". Department of Foreign Affairs and Trade (Government of Australia). Archived from the original on 20 February 2024. Retrieved 20 February 2024.
United States. Department of State. Bureau of Public Affairs (1989). "The Holy See". Backgr Notes Ser: 1–4. PMID12178005. Archived from the original on 23 January 2023. Retrieved 28 August 2023.
Galbreath, Donald Lindsay (13 September 1930). "A Treatise on Ecclesiastical Heraldry". W. Heffer and sons, Limited. Archived from the original on 10 March 2024. Retrieved 12 November 2020 – via Google Books.