@article{Bond:157745,
      recid = {157745},
      author = {Bond, J. J. and Umberger, D. E.},
      title = {Technical and Economic Causes of Productivity Changes in  U.S. Wheat Production, 1949-76},
      address = {1979},
      number = {1488-2016-124577},
      series = {Technical Bulletin},
      pages = {114},
      year = {1979},
      url = {http://ageconsearch.umn.edu/record/157745},
      doi = {https://doi.org/10.22004/ag.econ.157745},
}