Van de Geyn, W. A. E.; Van der Vlerk; I. M. (1935). A monograph on the Orbitoididae, occurring in the Tertiary of America, compiled in connection with an examination of a collection of larger foraminifera from Trinidad. Leidsche geologische Mededeelingen. 7 (2): 221-272.
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Van de Geyn, W. A. E.; Van der Vlerk; I. M.
1935
A monograph on the Orbitoididae, occurring in the Tertiary of America, compiled in connection with an examination of a collection of larger foraminifera from Trinidad.