http://imslp.org/wiki/Sue%C3%B1o_Tr%C3%A9molo_(T%C3%A1rrega,_Francisco)
http://es.cantorion.org/music/2285/Sue%C3%B1o-Tr%C3%A9molo-Tremelo
http://www.classclef.com/pdf/Sueno%20(Tremolo)%20by%20Francisco%20Tarrega.pdf