Why do babies cry? Excellent article in Archives of Paediatrics & Child Health.

https://adc.bmj.com/content/103/11/1077?hwoasp=authn%3A1541382715%3A5531204%3A1558872881%3A0%3A0%3AACgySl8bSyQx%2F16Ujbyd1g%3D%3D