1. Incorrect ballasting lowers performance;Pigg;Implement and Tractor,1990
2. A traction prediction and ballast selection model;Evans,1989
3. Automatic ballast position control for tractors;Zhang;Trans. ASAE,1989
4. Axle power distribution for a front-wheel assist tractor;Bashford;Trans. ASAE,1985
5. Dynamic-load and wheel-speed ratio effects on four-wheel drive tractive performance;Self,1988