DGS Publications
| Title | Authors | Publication Date |
|---|---|---|
| RI50 Plant Microfossils of the Calvert Formation of Delaware | Groot, J.J. | |
| B7 Engineering Materials of Northern New Castle County | Ward, R.F., Groot, J.J. | |
| B3 Marine Upper Cretaceous Formations of the Chesapeake and Delaware Canal | Organist, D.M., Richards, H.G., Groot, J.J. |