ZHEKOVA, Z. XII Международен симпозиум по Византийска сигилография 29 – 30 май 2019 г., Санкт-Петербург, Русия: 12 International Symposium on Byzantine Sigillography. 29th – 30th May 2019, Sant Petersburg, Russia. Numismatics, Sigillography and Epigraphy | Нумизматика, сфрагистика и епиграфика, [S. l.], v. 15, p. 201–204, 2019. Disponível em: https://publications.naim.bg/index.php/NSE/article/view/105. Acesso em: 8 oct. 2026.