Husein, I. R., M. Shiddiq, D. L. . Sari, and A. Putri. “Wavelength Dependence of Optical Electronic Nose for Ripeness Detection of Oil Palm Fresh Fruits”. Science, Technology, and Communication Journal, vol. 2, no. 3, June 2022, pp. 79-86, doi:10.59190/stc.v2i3.212.