1. Anonymous, 1984. The Seed Potatoes Regulations, 1984. Statutory Instrument No 412, 1984. Her Majesty's Stationery Office, London.
2. Dixon, W. J. (Ed.), 1983. BMDP Statistical software. University of California Press, Berkeley, CA.
3. Kirilin, N. I. & V. I. Starovoitov, 1979. Automatic grading of potatoes.Nauchi trudova na VIMMESS 21, ser 8, Izchislitelna tekhnika i Avtomatizatsiya na proizvodstvenite protsesi: 191–195.
4. Peleg, K., 1981. Quality criteria of sorting operations.Transactions of the American Society of Agricultural Engineers 24: 1459–1465.
5. Dep. Note SIN/239;R. L. Porteous,1977