Grupioni, Christina Maria de Freitas, et al. “Development and Evaluation of Operational Performance of Macaw Fruits Semi-Mechanized Harvester by Means Mechanical Vibrations Principle”. Semina: Ciências Agrárias, vol. 39, no. 2, Mar. 2018, pp. 497-10, doi:10.5433/1679-0359.2018v39n2p497.