https://uomosul.edu.iq/science/%d9%83%d9%84%d9%8a%d8%a9-%d8%a7%d9%84%d8%b9%d9%84%d9%88%d9%85-%d8%aa%d8%b9%d9%84%d9%86-%d8%b9%d9%86-%d9%86%d8%aa%d8%a7%d8%a6%d8%ac-%d8%a7%d9%84%d9%82%d8%a8%d9%88%d9%84-%d8%a7%d9%84%d8%a3%d9%88%d9%84-2/