"called Ballards made to stand a foot above the ground, hollow under, and hath uppon the top some seventeene woodden keyes standing like the Organ, upon which hee that playes sitting upon the ground, just against the middle of the instrument, strikes witha sticke in either hand, about a foote long, at the end whereof is made fast a round ball, covered with some soft stuffe, to avoyd the clattering noyse the bare stickes would make".Jobson 1968, p. 135 Jobson, Richard (1968) [1623], The golden trade or A discovery of the river Gambra, and the golden trade of the Aethiopians, London: Dawsons of Pall Mall
McPherson, Laura (2018-06-18). "Musical surrogate languages in the documentation of complex tone: The case of the Sambla balafon". 6th International Symposium on Tonal Aspects of Languages (TAL 2018). ISCA. pp. 62–66. doi:10.21437/tal.2018-13. S2CID52240848.
McPherson, Laura (2018-06-18). "Musical surrogate languages in the documentation of complex tone: The case of the Sambla balafon". 6th International Symposium on Tonal Aspects of Languages (TAL 2018). ISCA. pp. 62–66. doi:10.21437/tal.2018-13. S2CID52240848.