3Parish R L. Effect of rough operating surface on rotary spreader distribution pattern[J]. Applied Engineering In Agriculture ASAE, 1991,7(1),61-63.
4Olieslagers R, Ramon H, De Baerdemaeker J. Calculation of fertilizer distribution patterns from a spinning disc spreader by means of a simulationmodel[J]. Journal of Agricultural Engineering Research, 1996a, 63 (2), 137-153.
5Reetz H F. Site-specific nutrient management systems for the 1990s[J]. Better Crops with Plant Food, 1994,4:14-19.
6Morgan-Owen G J, Johnston G T. Differential GPS positioning[J]. Electronics and Communications Journal,Feb. 1995, 11-21. Institution of Electrical Engineers.
