Solodkiy V.I. Graduation qualification work: Third edition. / V.I.Solodky, Y.Y.Besarabets, V.V.Vovk, D.O.Krasnovyd. – Kyiv Igor Sikorsky Kyiv Polytechnic Institute-2021. – 220 p. The fretboard was provided by the Methodical Council of Igor Sikorsky Kyiv Polytechnic Institute. Protocol No. 2 dated 09.12.2021
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