Elsa María Cárdenas, and Luis Ulises Medina. “Non-Parametric Operational Modal Analysis Methods in Frequency Domain: A Systematic Review”. International Journal of Engineering and Technology Innovation 11, no. 1 (January 20, 2021): 34-44. Accessed February 26, 2021. https://ojs.imeti.org/index.php/IJETI/article/view/6126.