Gutenberg, B.; Richter, C. F. (July 1, 1942). "Earthquake magnitude, intensity, energy, and acceleration*". Bulletin of the Seismological Society of America. 32 (3): 112. doi:10.1785/BSSA0320030163. ISSN1943-3573.
Gutenberg, B.; Richter, C. F. (July 1, 1942). "Earthquake magnitude, intensity, energy, and acceleration*". Bulletin of the Seismological Society of America. 32 (3): 112. doi:10.1785/BSSA0320030163. ISSN1943-3573.