1. Armstrong G. (1777) An Account of the Diseases most Incident to Children. London; p. 128.
2. Astruc J. (1746) A General and Compleat Treatise on all the Diseases Incident to Children from their Birth to the Age of 15. London; p. 185.
3. Boerhaave H. (c. 1724) Quoted in: Anon (1742) A Full View of All the Diseases Incident to Children. London; p. 122.
4. Bracken H. (1737) The Midwife's Companion. London; p. 242.