DING, Chengqiao; WANG, Dachen; FENG, Zhe; CUI, Di. Detection of apple firmness with a novel loudspeaker-based excitation device. International Journal of Agricultural and Biological Engineering, Beijing, China, v. 15, n. 1, p. 260–266, 2022. Disponível em: https://ijabe.org/index.php/ijabe/article/view/7028. Acesso em: 3 feb. 2026.