BibCzechLing: 734 hits for Bulgarian on page 15

The "Bibliography of the Czech Linguistics (BibCzechLing)" is provided by the Institute of the Czech Language of the Academy of Sciences of the Czech Republic (Ústav pro jazyk český AV). The database contains about 73.280 records and covers the period from 1992 till 2018. The list of subjects is located here.

Your search for Bulgarian provides 734 hits
141	Bălgarskijat periodičen pečat i gradivnite knižnoezikovi procesi prez Văzraždaneto Ivanova, Diana Plovdiv 1994
142	Names, Ethnicity and Politics. Islamic Names in Bulgaria 1912-1992 Konstantinov, Yulian; Alhaug, Gulbrand Oslo 1995
143	Bulharština - praktický jazykový průvodce Český text Modlík, Tomáš Bučovice 1998
144	Stručná mluvnice bulharštiny Kufnerová, Zlata Praha 1990
145	Săvremenna bălgarska punktuacija Nicolova, Ruselina Sofija 1989
146	Žargonat, bez kojto (ne)možem Armjanov, Georgi Sofija 1989
147	Bolgarskij literaturnyj jazyk epochi Vozroždenija. Problemy normalizacii i vybora dialektnoj osnovy Venediktov, G. K. Moskva 1990
148	The genesis of the modern Bulgarian literary language Gyllin, Roger Uppsala 1991
149	Lekcii po bălgarska morfologija Kucarov, Ivan Plovdiv 1997
150	Češki stranici za Šumen prez Văzraždaneto Urban, Zdeněk; Vačkova, Kina Šumen 1995