Anta, Claudio Giulio. “Nicolas Murray Butler, an Advocate for the United States of Europe”. Rivista di studi politici internazionali 78, no. 3 (November 21, 2011). Accessed April 26, 2024. https://rosa.uniroma1.it/rosa00/index.php/studi_politici_internazionali/article/view/10280.