Gorsel, J. T. van <br/><br/>
Evolutionary trends and stratigraphic significance of the late cretaceous helicorbitoides-lepidorbitoides lineage / 
J. T. van Gorsel 
 - Utrecht :  Schotanus and Jens,  1975 
 - 99 p. :  ill. ;  25 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geology, Stratigraphic--Cretaceous