Author: Hofker, J., Jr., 1963.:
Title: Studies on the genus Orbitolina (Foraminiferida). [Leid. Geol. Meded., 29.]
Description: Leiden 1963. Pp. viii,253, many microphotos on 23 plates,10 charts, 24 figs., bibliogr. 4to. Orig. printed wrappers. - Doctoral thesis.

Keywords: