1. Low-frequency vibration detection device;Atanasoff,1956
2. A new vertical seismograph;Benioff;Bull. Seismol. Soc. Am.,1932
3. A reluctance seismograph for ultra long period waves;Benioff,1957
4. New results from long period seismographs;Benioff,1957
5. Measurements in the earth mode frequency range by an electrostatic sensing and feedback gravimeter;Block;J. Geophys. Res.,1966