Sales, Paul Ryan, Dorothy Emma C. Ferrer, Gayvelline C. Calacal, Jazelyn M. Salvador, & Maria Corazon A. De Ungria. " Validation of Two Extraction Methods for Human DNA from Cigarette Butts." Science Diliman: A Journal of Pure and Applied Sciences [Online], 31.1 (2019): n. pag. Web. 29 Aug. 2025