Alaa Ahmed Abdulwahed, Ali Hussein Hasan Al-Naily, Mazin Thamer Shnaef,. «A Study of the Concepts of Waste in the Textbooks of Sciences». Opción 350 (agosto 3, 2019): 730-741. Accedido agosto 3, 2025. http://www.produccioncientifica.luz.edu.ve/index.php/opcion/article/view/24548.