Trythall, Marisa Patrulli (2010). "Pius XI and American Pragmatism". In Gallagher, Charles R.; Kertzer, David I.; Melloni, Alberto (eds.). Pius XI and America: Proceedings of the Brown University Conference. Lit Verlag. p. 28. ISBN9783643901460.
Aradi, Zsolt (1958). Pius XI: The Pope and the Man. New York: Hanover House. ISBN9781787205000. Republished by Muriwai Books, 2017. Aradi counts one Italian too many and misses the Portuguese cardinal. He counts the Austrian serving as nuncio to Bavaria as Germany rather than Austrian.