Alciaturi C, Escobar M. Smoothing and derivative calculation of FT-IR spectra of coal by a modified least squares. REV TEC FAC ING UNIV [Internet]. 1 [citado 3 de agosto de 2025];17(1). Disponible en: http://www.produccioncientifica.luz.edu.ve/index.php/tecnica/article/view/5434