1. Evaluation of subsidence or collapse potential due to subsurface cavities;Benson,1984
2. A summary of methods for locating and mapping fractures and cavities with emphasis on geophysical methods;Benson,1992
3. Ground-penetrating radar enhances knowledge of Earth's surface layer;Mellett;Geotimes,1990
4. Development of sinkholes resulting from man's activities in the eastern United States;Newton;US Geol. Surv. Circ.,1986
5. Application of impulse radar to civil engineering;Ulriksen,1982