These guidelines were recently cited in the following. Perhaps the researchers have a copy. Also, there is a link to book chapter discussing the guidelines below.
Lazarus G. Ndatuwong, G. S. Yadav. Integration of Hydrogeological Factors for Identification of Groundwater Potential Zones Using Remote Sensing and GIS Techniques. Journal of Geosciences and Geomatics. 2014; 2(1):11-16. doi: 10.12691/jgg-2-1-2. (Department of Geophysics, Banaras Hindu University, Varanasi, India; Department of Physics, Adamawa State University, Mubi, Nigeria)