Dochev, K. Монети и парично обръщение в Търново XII-XIV в. (Tirnovo, 1992).
Coins and Coin Usage in Turnovo (XII-XIV c.)
In Bulgarian, 64 tables with excellent drawings of the majority of the copper coins issued between the reign of Alexius I and John V Paleologus. Softcover, 317pp., 24 b/w plates. This is an absolutely must have for any collector interested in late Byzantine period.
Also see:
Dochev 2017