@article{Benjamin:138480,
      recid = {138480},
      author = {Benjamin, Gary L. and Langford, Don A.},
      title = {Agricultural Letter},
      journal = {Agricultural Letter},
      address = {1978-04-21},
      number = {820-2016-52901},
      series = {1471},
      pages = {4},
      month = {Apr},
      year = {1978},
      url = {http://ageconsearch.umn.edu/record/138480},
      doi = {https://doi.org/10.22004/ag.econ.138480},
}