1. Annan AP (2009) Electromagnetic principles of ground penetrating radar. In: Jol HM (ed) Ground penetrating radar: theory and applications, 2009. Elsevier, Solvenia, pp 4–40
2. Aqeel AM (2012) Measuring the orientations of hidden subvertical joints in highways rock cuts using ground penetrating radar in combination with LIDAR. Dissertation, Missouri University of Science and Technology
3. Bieniawski ZT (1989) Engineering rock mass classification: a complete manual for engineers and geologists in mining, civil, and petroleum engineering. Wiley, Canada
4. Beres M Jr, Haeni FP (1991) Application of ground-penetrating-radar methods in hydrogeologic studies. Ground Water 29(3):375–386
5. Booth AD, Endres AL, Murray T (2009) Spectral bandwidth enhancement of GPR profiling data using multiple-frequency compositing. J Appl Geophys 67:88–97