@article{valliant_1973, 
  title={A Technique for the Precise Calibration of Continuously Recording Gravimeters}, 
  volume={274}, 
  DOI={10.1098/rsta.1973.0047}, 
  number={1239}, 
  publisher={The Royal Society}, 
  author={Valliant}, 
  year={1973}, 
  month={May}
  }