Dobrovolsky, A.A.; Lemanov, V.V.; Sherman, A.B.; Gal'perin, Yu.M.; Kozub, V.I.: 'Nonlinear interaction of s.a.w.s in piezoelectric crystals with secondary electrons', Electronics Letters, 1980, 16, (7), p. 243-244, DOI: 10.1049/el:19800179
IET Digital Library, https://digital-library.theiet.org/;jsessionid=2148nmwekv5hf.x-iet-live-01content/journals/10.1049/el_19800179