1. Anderson N, Ismail A (2003) A generalized protocol for selecting appropriate geophysical techniques. Geophysical Technologies for detecting Underground Coal Mine Voids Forum, Lexington, KY
2. Anderson N et al (2003) Selection of appropriate techniques: a generalized protocol based on engineering objectives and site characteristics. Presented at the 3rd international conference on applied geophysics, Orlando, FL, 8–11 Dec 2003
3. Armstrong FE, Heemstra RJ (1973) Radiation halos and hydrocarbon reservoirs: a review. US Department of the Interior, Bureau of Mines, Information Circular 8579
4. ASTM (2007) Standard guide for the use of the time domain electromagnetic method for subsurface investigation. Designation: D6820-02. American Society for Testing Materials, Philadelphia
5. ASTM (2008) Standard guide for using the frequency domain electromagnetic method for subsurface investigation. Designation: D6639-01. American Society for Testing Materials, Philadelphia