• Wave equations in mechanicsEngelbrecht, JüriEstonian journal of engineering2013 / p. 273-282 https://doi.org/10.3176/eng.2013.4.02 https://www.scopus.com/record/display.uri?eid=2-s2.0-84890294747&origin=resultslist&sort=plf-f&src=s&sot=b&sdt=b&s=DOI%2810.3176%2Feng.2013.4.02%29&sessionSearchId=08e7c58f88aea92900d731f06ee215ed