Khalid Abdilrazzaq T. The effect of circular holes on the natural frequencies of a beam using transverse vibration measurements method _ENG. AREJ [Internet]. 2013 Apr. 1 [cited 2025 Oct. 2];21(2):13-24. Available from: https://jcis.uomosul.edu.iq/index.php/arej/article/view/31473