@article{Heffernan:137341,
      recid = {137341},
      author = {Heffernan, Peter J.},
      title = {Agricultural Letter},
      journal = {Agricultural Letter},
      address = {1988-06-03},
      number = {820-2016-53263},
      series = {1735},
      pages = {4},
      month = {Jun},
      year = {1988},
      url = {http://ageconsearch.umn.edu/record/137341},
      doi = {https://doi.org/10.22004/ag.econ.137341},
}