1. Tractors and fuel efficiency;Bigsby;Agrologist,1981
2. Handbook of Industrial Energy Analysis;Boustead,1979
3. Fundamentals of Machinery Operation;Bowers,1981
4. Application of mathematical formulas to repair cost data;Bowers;Trans. ASAE,1970
5. A method for determining the total energy input for agricultural practices;Bridges;Trans. ASAE,1979