- National Library in Warsaw
- https://www.bn.org.pl
- Library
- Russian National Library in St. Petersburg
- https://nlr.ru/eng
- Library
- ACCL
- https://calic-bg.eu
- Academic circle of comparative literature – ACCL
- Scripta & e-Scripta
- https://www.ceeol.com/search/journal-detail?id=953
- Peer-reviewed international periodical
- „Старобългарска литература“
- http://www.starobulglit.eu
- Medieval Bulgarian Literature
- Българистика/Bulgarica (from 2004)
- https://www.ceeol.com/search/journal-detail?id=1256
- History, Social Sciences, Language and Literature Studies
- Литературна мисъл
- https://litmis.eu
- History, criticism and comparative studies
- Ulrich's Periodicals Directory
- https://ulrichsweb.serialssolutions.com/login
- Ulrich's Serials Analysis System
- BIBP Base d'Information Bibliographique en Patristique
- https://www4.bibl.ulaval.ca/bd/bibp/
- Indexed in The Bibliographic Information Base in Patristics (BIBP)
- Brepolis
- https://apps.brepolis.net/BrepolisPortal/default.aspx
- International Medieval Bibliography
- Byzantinische Zeitschrift
- https://www.degruyterbrill.com/journal/key/byzs/html
- Reference in: Byzantinische Zeitshrift (from 2004)
- Institute for Literature
- https://ilit.bas.bg
- Institute for Literature - Bulgarian Academy of Science
- Publishing Centre "Boyan Penev"
- https://ilitizda.com
- Specialized publishing
- CEEOL
- https://www.ceeol.com
- Central and Eastern European Online Library
- Balkan Identities
- https://balkansbg.eu
- Interdisciplinary project
