Wason, H. R. and Das, Ranjit and Sharma, M. L.  (2012) Magnitude conversion problem using general orthogonal regression.  Geophysical Journal International, 190 (2).  pp. 1091-1096. DOI: https://doi.org/10.1111/j.1365-246X.2012.05520.x <https://doi.org/10.1111/j.1365-246X.2012.05520.x>