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 Nov. 5];21(2):13-24. Available from: https://berj.uomosul.edu.iq/index.php/arej/article/view/31473