SPEISER, D. The Symmetries of the Battistero and the Torre pendente in Pisa. An Attempt at a Chronological Reconstruction. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI LETTERE E FILOSOFIA, Pisa, Italia, v. 24, p. 511-564, Disponível em: https://journals.sns.it/index.php/annalilettere/article/view/3794. Acesso em: 20 feb. 2026.