Dolgin, Alexander (2008). The Economics of Symbolic Exchange. Springer Science & Business Media. p. 228. ISBN9783540798828. Consultado el 3 de diciembre de 2014. «Word of mouth can overcome the information cascade devised by marketing specialists. This is important as objective testimony to the power of the bush telegraph.»
" Luther asserted, 'It is the manner of the New Testament and of the gospel that it must be preached and performed by word of mouth and a living voice. Christ himself has not written anything, not has he ordered anything to be written, but rather to be preached by word of mouth.'" Quoted in:
Whitford, David M (2014). «Preaching and Worship». T&T Clark Companion to Reformation Theology. Bloomsbury Companions. Bloomsbury Publishing. p. 161. ISBN9780567445087. Consultado el 3 de diciembre de 2014.
