Bretas, W. V., A. S. C. Morais, H. R. M. da Hora, and E. T. Azevedo Filho. “Knowledge Extraction on International Markets from Patent Bases: A Study on Green Patents”. Brazilian Journal of Operations & Production Management, vol. 16, no. 4, Dec. 2019, pp. 698-05, doi:10.14488/BJOPM.2019.v16.n4.a14.