https://uomosul.edu.iq/science/%d8%aa%d8%af%d8%b1%d9%8a%d8%b3%d9%8a-%d9%85%d9%86-%d9%83%d9%84%d9%8a%d8%aa%d9%86%d8%a7-%d9%8a%d8%b4%d8%a7%d8%b1%d9%83-%d8%a8%d8%b9%d8%b6%d9%88%d9%8a%d8%a9-%d9%84%d8%ac%d9%86%d8%a9-%d9%85%d9%86%d8%a7-3/