Nikolov, P. 1993. Some molluscs from the Badenian (Middle Miocene) west of Pleven (Central Northern Bulgaria). I. Gastropoda: orders Archaeogastropoda and Mesogastropoda. - Geologica Balc., 23, 6; 61-72.
Nikolov, P. 1994. Some molluscs from the Badenian (Middle Miocene) west of Pleven (Central Northern Bulgaria). II. Gastropoda: order Neogastropoda. - Geologica Balc., 24, 4; 45-70.
Nikolov, P. 1995. Planktonic gastropods of the Badenian near the village of Urovene, NW Bulgaria. - C. R. Acad. Bulg. Sci., 48, 11-12; 71-74.
Nikolov, P. 1995. Some molluscs from the Badenian (Middle Miocene) west of Pleven (Central Northern Bulgaria). III. Bivalvia. - Geologica Balc., 25, 5-6; 127-143.
Popov, S., Gontsharova, I., Nikolov, P., Studencka, B. 1996. Bivalve molluscs from the Badenian of Northwestern Bulgaria. - Paleontologicheskij journal, 2; 34-42 (in Russian with English abstract).
Nikolov, P. 1999a. Taxonomical structure and paleoecology of shallow-water Tarkhanian molluscan assemblage from the Lower-Kamchia depression, Northeastern Bulgaria. - Rev. Bulg. Geol. Society, 60, 1-3; 39-47 (in Bulgarian with English abstract).
Nikolov, P. 1999b. Taxonomical structure and age of the molluscan fossil community from the Karapelit Formation, Northeastern Bulgaria. - Rev. Bulg. Geol. Society, 60, 1-3; 119-126 (in Bulgarian with English abstract).
Nikolov, P., Ivanov, P., Berov, B., Hristoskov, L., Solakov, D., Simeonova, S. 2000. Geology and Seismicity. In: Popov, A. et al. (Eds). Sofia - 120 years capital. - Acad. publ. house “Prof. M. Drinov”, Sofia; 44-48 (in Bulgarian).
Nikolov, P. 2002. About the extinction of the molluscan fauna in the Euxinian basin up to the begining of the Late Chokrakian Subage. - Int. Sc. Conf. in Memory of Prof. D. Jaranov, Varna 2002. Proceedings, vol. 2; 28-35 (in Bulgarian with English abstract).
Nikolov, P. 2003. Middle Miocene Subseries in part of Northeastern Bulgaria - chronostratigraphy and correlations. - Geologica Balc.,32,2-4;69-72.
Last update 9 February 2004