1. Barnhisel R I; Bitzer M J; Grove J H (1996). Agronomic benefits of varying corn seed populations: a Central Kentucky study. In: Precision Agriculture: Proceedings of the Third International Conference (Robert P C; Rust R H; Larson W E, eds), pp. 957–965. ASA, CSSA, SSSA, Madison, WI, USA
2. Birrell S J; Sudduth K A; Borgelt S C (1996). Comparison of sensors and techniques for crop yield mapping. Computers and Electronics in Agriculture, 14, 215–233
3. Boissard P; Boffety D; Devaux J F; Zwaenepoel P; Huet P; Gilliot J -M; Heurtaux J; Troizier J (2001). Mapping of the wheat leaf area from multidate radiometric data provided by on board sensors. In: Proceeding of the Third European Conference on Precision Agriculture (Grenier G; Blackmore S, eds) pp 157–162. Montpellier, France
4. Earl R; Wheeler P N; Blackmore B S; Godwin R J (1996). Precision farming the management of variability. Landwards, Journal of the Institution of Agricultural Engineers, 51(4), 18–23
5. Godwin R J; James I T; Welsh J P; Earl R (1999). Managing spatially variable nitrogen—a practical approach. Presented at the: ASAE/CSAE-SCGR Annual International Meeting, Paper No. 99-1142. Toronto, Ontario, Canada