@article{Heffernan:137210,
      recid = {137210},
      author = {Heffernan, Peter J. and Benjamin, Gary L.},
      title = {Agricultural Letter},
      journal = {Agricultural Letter},
      address = {1990-05-04},
      number = {820-2016-53036},
      series = {1785},
      pages = {4},
      month = {May},
      year = {1990},
      url = {http://ageconsearch.umn.edu/record/137210},
      doi = {https://doi.org/10.22004/ag.econ.137210},
}