Nogueira, Guilherme Augusto Lisboa, et al. “Study of Portuguese Coins Issued During the Reign of D. João With PXRF Technique and Multivariate Analysis”. Semina: Ciências Exatas E Tecnológicas, vol. 46, Sept. 2025, p. e52402, doi:10.5433/1679-0375.2025.v46.52402.