1. ASABE Standards 1996: Standards engineering practices data,1996
2. ASAE Standards 2006: Standards engineering practices data,2006
3. Power demand and soil mobilization in fixed shanks of seed drills;Cepik C. T. C.;Revista Brasileira de Engenharia Agrícola e Ambiental,2010
4. Crop-livestock integration: Benefits of perennial grasses in production systems;Crusciol C. A .C.;Informações Agronômicas,2009
5. Brazilian system of soil classification,2006