Basheer Abdullah, D., and ضحى. “Design and Analysis of a Sound Generator for Wave File Format via Parallel Printer Port”. AL-Rafidain Journal of Computer Sciences and Mathematics, vol. 6, no. 1, Jan. 2009, pp. 49-61, https://tanmiyat.uomosul.edu.iq/index.php/csmj/article/view/36913.