Mathematical modelling of monetary minting in mediaeval Bulgaria Jordan Tabov; Kliment Vasilev; Asen Velchev — 2004 Review of the National Center for Digitization
Chronological distribution of the coin finds in Bulgaria for a quarter century (1910-1934) Jordan Tabov; Kliment Vasilev; Asen Velchev — 2005 Review of the National Center for Digitization