REIS, M.; REIS, P.; MARTINEZ, M. E.; LOPES, Y.; GUIMARÃES, G.; DE OLIVEIRA, A. M. Study on the Innovation Process in Precision Agriculture using patent mapping using NPK sensors in the production of fertilizers. Journal of Mechatronics Engineering, [S. l.], v. 4, n. 1, p. 2–11, 2021. DOI: 10.21439/jme.v4i1.87. Disponível em: https://jme.ifce.edu.br/index.php/jme/article/view/87. Acesso em: 4 aug. 2025.