@article{ferreira_oliveira júnior_castelar_2012,  title={Modelos de índice de difusão para prever a taxa de crescimento do PIB agrícola brasileiro},  volume={22},  ISSN={0103-6351},  url={https://doi.org/10.1590/S0103-63512012000100004},  DOI={10.1590/S0103-63512012000100004},  number={1},  journal={Nova Economia},  publisher={Nova Economia},  author={Ferreira, Roberto Tatiwa and Oliveira Júnior, José Nilo de and Castelar, Ivan},  year={2012},  month={Jan},  pages={117–139} }