Samila, A. P., A. G. Khandozhko, and A. G. Khandozhko. “The Continuous Wave NQR Spectrometer With Equidistant Frequency Scale”. Technology and Design in Electronic Equipment, no. 5–6, Dec. 2010, pp. 17-21, https://www.tkea.com.ua/index.php/journal/article/view/TKEA2010.5-6.17.