@misc{770176,
  author = {A. Yaghjian},
  title = {An Approximate Expression for the Principal Beamwidth ofDirective Antennas in Terms of Aperture Fields},
  year = {1981},
  month = {1981-03-01 00:03:00},
  publisher = {NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD},
  language = {en},
}