OVCHAROV, V. Billon (?) Coinage of King Ivan Shishman (1371–1375): A Structural Investigation. Bulgarian Numismatic Journal, [S. l.], v. 2, n. 1, p. 11–18, 2024. DOI: 10.5281/zenodo.11076664. Disponível em: https://bulgnj.com/index.php/e-journal/article/view/63. Acesso em: 28 apr. 2025.