The Mobile Application Development Based on Online Music Library for Socializing in the World of Bard Songs and Scouts’ Bonfires - Bohdan Rusyn; Liubomyr Pohreliuk; Antonii Rzheuskyi; Roman Kubik; Yuriy Ryshkovets; Lyubomyr Chyrun; Sofiia Chyrun; Anatolii Vysotskyi; Vitor Basto-Fernandes (Springer Advances in Intelligent Systems and Computing IV, 2020)