Pearce, E., Launay, J., Machin, A., & Dunbar, R. (1969). Is group singing special? Health, well-being and social bonds in community-based adult education classes. Journal of Community & Applied Social Psychology, 26(6), 518-533. https://doi.org/10.1002/casp.2278 (Original work published 1969)

Pearce, E., Launay, J., & Dunbar, R. (2015). The ice-breaker effect: singing mediates fast social bonding. Royal Society Open Science, 2(10), 150221. https://doi.org/10.1098/rsos.150221