The Paleocene-Eocene transition in Bulgaria: inference from calcareous nannofossils
Kristalina Stoykova (a) (a) Department of Paleontology, Stratigraphy and Sedimentology, Geological Institute Bulgarian Academy of Sciences, 24 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria. E-mail: stoykova@geology.bas.bg