1. Lundberg U. Catecholamines. In: Fink G, editor. Encyclopedia of stress. Vol. 2. San Diego: Academic Press; 2000. pp 408–413.
2. Dallman M, Bhatnagar S, Viua V. Hypothalamo-pituitaryadrenal axis. In: Fink G, editor. Encyclopedia of stress. Vol. 2. San Diego: Academic Press; 2000. pp 468–477.
3. Kerlinger FN. Foundations of behavioral research. London: Holt-Saunders International Editions; 1979. pp 442–445.
4. Kwast BE. World Health Organisation partograph in management of labour. Lancet 1994; 343: 1399–1404.