C. F. Chaves-Cordero and C. Escamilla-Fonseca , Trans., “Choral Conducting Studies and Tools Required for the Development of Children´s Choirs. Current Situation in Costa Rica and Spain”, Rev. Electr. Educare, vol. 21, no. 1, pp. 1–23, Jan. 2017, doi: 10.15359/ree.21-1.5.