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 5 de marzo de 2026];17(1). Disponible en: http://mail.produccioncientificaluz.org/index.php/tecnica/article/view/5434