@article{Benjamin:137497, recid = {137497}, author = {Benjamin, Gary L. and Heffernan, Peter J.}, title = {Agricultural Letter}, journal = {Agricultural Letter}, address = {1987-05-22}, number = {820-2016-52942}, series = {1708}, pages = {4}, month = {May}, year = {1987}, url = {http://ageconsearch.umn.edu/record/137497}, doi = {https://doi.org/10.22004/ag.econ.137497}, }