A. Mossa, Mekhaiel. “Theoretical Study of Longitudinal Vibrations of Two Coupled Crystal Slabs Using Difference Equations Method”. Rafidain Journal of Science 16, no. 4 (March 1, 2005): 89–94. Accessed September 29, 2025. https://jwups.uomosul.edu.iq/index.php/rsci/article/view/46702.