M. D. P. Ferreira, L. O. de Sousa, E. C. Teixeira, and A. C. Campos, “The role of Sale Option Contracts in the coffee crisis of 2002 and 2003”, Rev. Polit. Agric., vol. 18, no. 3, pp. 85–97, Jun. 2015, Accessed: Sep. 20, 2026. Available: https://rpa.sede.embrapa.br/RPA/article/view/390