DGS Publications
| Title | Authors | Publication Date |
|---|---|---|
| RI58 The Pliocene and Quaternary Deposits of Delaware: Palynology, Ages, and Paleoenvironments | Groot, J.J., Jordan, R.R. | |
| RI55 Geology of the Milford and Mispillion River Quadrangles | Ramsey, K.W., Groot, J.J. | |
| OFR13 Delaware's Extractive Mineral Industry | Doyle, R.G., Pickett, T.E. | |
| B7 Engineering Materials of Northern New Castle County | Ward, R.F., Groot, J.J. |