Technical papers and some manuals can be downloaded from Manufacturers websites. Geometrics: To download information about magnetometers and seismographs go to Geometrics Website; Click on the downloads button at the top of the page. You are offered a choice of Seismographs or Magnetometers. Click on the appropriate button.
Here are a few links to external sites in which you can gain some more information about Geoscience and Geophysical Sciences. Advanced Geosciences Inc. (AGI), Association of Engineering Geologist (AEG), Environmental and Engineering Geophysical Society (EEGS), Geomar Software Inc.