Bormann, P. & Dewey, J. W.: ”Information Sheet 3.3: The new IASPEI standards for determining magnitudes from digital data and their relation to classical magnitudes”, New Manual of Seismological Observatory Practice 2 (NMSOP-2). IASPEI, GFZ German Research Centre for Geosciences, Potsdam, 2014. Teoksen verkkoversio. (englanniksi) (Arkistoitu – Internet Archive)
Bormann, P. & Dewey, J. W.: ”Information Sheet 3.3: The new IASPEI standards for determining magnitudes from digital data and their relation to classical magnitudes”, New Manual of Seismological Observatory Practice 2 (NMSOP-2). IASPEI, GFZ German Research Centre for Geosciences, Potsdam, 2014. Teoksen verkkoversio. (englanniksi) (Arkistoitu – Internet Archive)