Nacionalna bibliografija na N.R. Bulgaria (The National Bibliography of Bulgaria): Series 1. Bălgarski knigopis. Knigi notni, grafičeski i kartografski izdanija. Dvusedmičen bjuletin. (Bălgarski knigopis. Books, music, graphic and cartographic materials. Fortnightly). 1897. Bălgarski knigopis. Knigi, notni, grafičeski i kartografski izdanija. Obšt godišen ukazatel (Bălgarski knigopis. Books, music, graphic and cartographic materials. Annual directory). 1969.
2.
Series 2. Bălgarski knigopis. Služebni izdanija i disertacii. Mesečen bjuletin (Bălgarski knigopis. Official publications and dissertations. Monthly). 1962. Bălgarski disertacii. Obšt godišen ukazatel. Bulgarian dissertations. Annual directory). 1973.
3.
Series 3. Bălgarski gramofonni ploči. Godišen ukazatel (Bulgarian gramophone records. Annual directory).
4.
Series 4. Bălgarski periodičen pečat. Vestnici, spisanija, bjuletin i periodični sbornici (Bulgarian periodicals. Newspapers, magazines, bulletins and periodical collections. Annual directory). 1965.
5.
Series 5. Letopis na statiite ot bălgarskite spisanija i sbornici. Dvusedmicen bjuletin (Index bibliography of articles appearing in Bulgarian magazines and periodical collections. Fortnightly). 1952.
6.
Series 6. Letopis na statiite ot bălgarskite vestnici (Indexing bibliography of articles appearing in Bulgarian newspapers. Monthly). 1972.
7.
Series 7. Bulgaria v čuzdata literatura. Bulgaria. Godišen ukazatel (Bulgaria in the foreign literature. Bulgaria. Annual directory). 1964.
8.
Line, M.B.Universal availability of publications. Unesco Bulletin for Libraries, 31 (3), 1977, 142-51.
9.
Kalajdžieva, K.Problemi pred săvremennata nacionalna bilioteka pri obslužvaneto na naučnija i tekničeski progress (Problems of the modern national library in assisting the progress of science and technology). Izvestija na NBKM, 6, 1968, 13-36.
10.
Kalajdžieva, K. and H. Hadžihristov.Edno nabljudenie vărhu izpolzuvanata naučna periodica v Narodna biblioteka 'Kiril i Metodij' (A study of the use of scientific periodicals at the Cyril and Methodius National Library). Izvestija na NBKM, 6, 1968, 257-278; Kalajdžieva , K. and H. Hadžihristov.Rezultati ot pročvaneto na čitatelskite interesi na njakoi kategorii naučni rabotnici i specialisti (Results obtained from the study of the reading interests of some categories of researchers and specialists). Ibid., 163-257.
11.
Bower, C.A.Patterns of use of the serial literature at the BLLD. BLL Review, 4 (2), 1976, 31-36.
12.
Čuždi periodični izdanija v po-golemite naučni biblioteki v Bulgaria. Svoden katalog 1900 1958 (Foreign periodicals in possession of major libraries in Bulgaria. A union catalogue, 1900-1958) . Sofia: NBKM, 1963. (to be continued)
13.
Bjuletin za novonabaveni knigi na čuždi ezici. Mes. izd. (Accession bulletin of newly-acquired books in foreign languages. Monthly). 1954. Series A. Mathematics, physics, chemistry, geology, geography, technology, industry; Series B. Biology and medicine; Series C. Agriculture; Series D. Social sciences, philology, art.