@article{Heffernan:137526,
      recid = {137526},
      author = {Heffernan, Peter J.},
      title = {Agricultural Letter},
      journal = {Agricultural Letter},
      address = {1984-08},
      number = {820-2016-53381},
      series = {1637},
      pages = {4},
      year = {1984},
      url = {http://ageconsearch.umn.edu/record/137526},
      doi = {https://doi.org/10.22004/ag.econ.137526},
}