Worku, Asrat. 2023. “A CLOSED-FORM SOLUTION PROCEDURE TO THE VIBRA TlON OF NON-CLASSICALLY DAMPED SYSTEMS SUBJECTED TO HARMONIC LOADS”. Zede: Journal of Ethiopian Engineers and Architects የኢትዮጵያ መሐንዲሶችና አርክቴክቶች መጽሔት 22 (January):1-9. https://ejol.aau.edu.et/index.php/ZEDE/article/view/6515.