SolodkiyV.I. Master’s thesis. Scientific component / V.I. Solodkiy, V.V. Vovk, D.O. Krasnovid – Kyiv Igor Sikorsky Kyiv Polytechnic Institute. – 2021. – 156 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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