@misc{1155031,
  author = {R E McDuffie},
  title = {Tables of median hourly values of the cosine of the solar zenith angle (x) for thirty-five locations.:},
  year = {1959},
  month = {1959-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NBS.TN.5},
  language = {en},
}