@article{rabello_cruvinel_2009,  title={Intelligent instrument to facilitate decision making in the evaluation of soil resistance to root penetration},  volume={66},  ISSN={0103-9016},  url={https://doi.org/10.1590/S0103-90162009000500001},  DOI={10.1590/S0103-90162009000500001},  number={5},  journal={Scientia Agricola},  publisher={Escola Superior de Agricultura "Luiz de Queiroz"},  author={Rabello, Ladislau Marcelino and Cruvinel, Paulo Estevão},  year={2009},  month={Sep},  pages={573–582} }