@book{snapper_inglis_1977, 
  title={SKED software system. Revision D. Time-shared SUPERSKED. Manual 3}, 
  DOI={10.2172/6312509}, 
  institution={Office of Scientific and Technical Information  (OSTI)}, 
  author={Snapper and Inglis}, 
  year={1977}, 
  month={Jan}
  }