@misc{indiciae1bcc9fbd4fbd,
  title = {Broadband microwave waveguide window Patent},
  author = {Mullen, D. L. and Stelzried, C. T.},
  year = {1968},
  url = {https://ntrs.nasa.gov/citations/19710015332},
  note = {Source identifier: 19710015332}
}