Daniel Rouseff, Robert P. Porter, Warren L. J. Fox; Acoustical characterization of a shallow water environment from sparse data, Proceedings of IEEE OCEANS'93 Conference, pp. 71 - 75, October 1993.

Robert C. Spindel, Robert P. Porter, John A. Schwoerer; Acoustic phase tracking of ocean moorings, IEEE J. Oceanic Eng., vol. 3, pp. 27 - 30, January 1978.

Robert C. Spindel, Robert P. Porter, Douglas C. Webb; A mobile coherent low-frequency acoustic range, IEEE J. Oceanic Eng., vol. 2, pp. 331 - 337, October 1977.

Robert C. Spindel, Robert P. Porter, William M. Marquet, James L. Durham; A high-resolution pulse-Doppler underwater acoustic navigation system, IEEE J. Oceanic Eng., vol. 1, pp. 6 - 13, September 1976.

R. C. Spindel, J. L. Durham, R. P. Porter; Performance analysis of deep ocean acoustic navigation systems, Proceedings of MTS/IEEE OCEANS'75 Conference, pp. 568 - 572, September 1975.

R. C. Spindel, R. P. Porter; Precision tracking systems for sonobuoys, OCEANS'74 --- IEEE International Conference on Engineering in the Ocean Environment, pp. 162 - 165, August 1974.