Keynote address and discussion, 7th annual conference : 'Precision agriculture - practical applications of new technologies' /
Gummer, John Selwyn,1939-
International Fertiliser Society.Conference(7th :1998 :Cambridge, England)
York : International Fertiliser Society,
c1999.
"Presentations to the International Fertiliser Society at a conference in Cambridge, UK, on 11-12th December 1998".
Precision farming