USTINSKOVS, Jevgeņijs. Kinds of Improvisation Activity in Music Secondary Schools. SOCIETY. INTEGRATION. EDUCATION. Proceedings of the International Scientific Conference, Rezekne, Latvia, v. 1, p. 163–171, 2015. DOI: 10.17770/sie2012vol1.32. Disponível em: https://archive-journals.rtu.lv/sie/article/view/703.. Acesso em: 11 mar. 2026.