@article{Heffernan:136292,
      recid = {136292},
      author = {Heffernan, Peter J.},
      title = {Agricultural Letter},
      journal = {Agricultural Letter},
      address = {1984-02},
      number = {820-2016-53377},
      series = {1622},
      pages = {4},
      year = {1984},
      url = {http://ageconsearch.umn.edu/record/136292},
      doi = {https://doi.org/10.22004/ag.econ.136292},
}