A palynological study of the tertiary and upper cretaceous of British Guiana /
by T. van der Hammen and T.A Wymstra .-
- Leiden : Geologischen Mineralogisch Institut des Rujksuniversiteit, 1964.
- p. 183-241 and 7 p. of plates : ill., diagrs., graphs. maps, photos, ports.
Offprint from: Leidse geologische mededelingen, 1964 ; p. 183-241.