@book{demarcus_jenkins, jr_1957, 
  title={THE PROBLEM OF KNUDSEN FLOW.  PART VI. TORTUOSITY}, 
  DOI={10.2172/4362793}, 
  institution={Office of Scientific and Technical Information (OSTI)}, 
  author={DeMarcus and Jenkins, Jr}, 
  year={1957}, 
  month={Sep}
  }