$100 — Power System Grounding and Transients by A.P. "Sakis" Meliopoulos, second printing (Marcel Dekker Inc., 1988)
IEEE Std. 80, IEEE Guide for Safety in AC Substation Grounding, 2000 edition — Purchase directly from IEEE.
IEEE Std. 81, IEEE Guide for Measuring Earth Resistivity, Ground Impedance and Earth Surface Potentials of a Ground System — Purchase directly from IEEE.