@article{Padberg:243902, recid = {243902}, author = {Padberg, D.I. and Westgren, R.E.}, title = {Direct Marketing in Perspective}, address = {1980-12}, number = {1632-2016-135045}, series = {Staff Paper}, pages = {11}, year = {1980}, url = {http://ageconsearch.umn.edu/record/243902}, doi = {https://doi.org/10.22004/ag.econ.243902}, }