1. J. W. Barker(1978 ), Possible New Markets-Direct Farm Sales. Unpublished conference paper, Department of Agricultural Marketing, University of Newcastle upon Tyne.
2. J. W. Barker(1979 ), A Personal Interview Survey of Farmers Involved with Some Form of Direct Marketing- A Summary of Results. Unpublished mimeo report, Department of Agricultural Marketing, University of Newcastle upon Tyne.