References
- Bouwer , H. 1990 . Agricultural chemicals and groundwater quality . Journal of Soil and Water Conservation , 45 ( 2 ) : 184 – 189 .
- Brown , L. , Flavin , C. , French , H. , Jacobson , J. , Lowe , M. , Postel , S. , Renner , M. , Starke , L. and Young , J. 1990 . State of the world , New York : Norton .
- Bruening , T. and Martin , R. A. 1992 . Farmers' perceptions of soil and water conservation issues: Implications to agricultural and extension education . Journal of Agricultural Education , 33 ( 4 ) : 48 – 54 . Winter
- Campbell , D. T. and Stanley , J. C. 1963 . Experimental and quasi-experimental designs for research , Boston : Houghton Mifflin .
- Carriker , R. , Purvis , A. and Mapp , H. P. 1990 . Agricultural and water quality: Old problem, new urgency, discussion . Southern Journal of Agricultural Economics , 22 ( 1 ) : 27 – 32 . 41 – 46 .
- Crocker , T. D. , Forster , B. A. and Shogen , J. F. 1991 . Valuing potential groundwater protection benefits . Water Resources Research , 27 ( 1 ) : 1 – 6 .
- Dillman , D. 1978 . Mail and telephone surveys: The total design method , New York : Wiley-Interscience .
- Elnagheeb , A. H. , Jordan , J. L. and Humphrey , V. 1995 . The structure of farmers' perceptions of groundwater pollution . Journal of Agricultural Economics , 27 ( 1 ) : 224 – 237 .
- Lichtenberg , E. and Lessley , B. V. 1992 . Water quality, cost sharing, and technical assistance: Perceptions of Maryland farmers . Journal of Soil and Water Conservation , 47 ( 3 ) : 260 – 264 .
- Miller , L. E. and Smith , K. L. 1993 . Handling non-response issues . Journal of Extension , 21 ( 5 ) : 45 – 50 .
- Napier , T. L. and Brown , D. E. 1993 . Factors affecting attitudes toward groundwater pollution among Ohio farmers . Journal of Soil and Groundwater Conservation , 48 ( 5 ) : 432 – 438 .