1. Armstrong, B. K., White, E. & Saracci, R. (1992).Principles of exposure measurement in epidemiology(Vol. 21). Oxford, UK: Oxford University Press.
2. Australian Nursing Federation (Vic) Maternal and Child Health Special Interest Group (ANF MCH SIG). (2004).Exploration of maternal and child health nursing practice in Victoria, Australia 2001–2003: Issue paper, February 2004. Melbourne, VIC: Australian Nursing Federation.
3. De Vaus, D. (2004). Structure questionnaires and interviews. In V. Minichiello, G. Sullivan, K. Greenwood, & R. Axford (Eds.),Handbook of research methods for nursing and health science(2nd ed., pp. 347–390). Frenchs Forest, NSW: Pearson Education.
4. Stata Statistical Software. (2007).Release 1 [program]. College Station, TX: StataCorp LP.
5. Taylor, B., Kermode, S. & Roberts, K. (2007).Research in nursing and health care: Evidence for practice(2nd ed). Melbourne, VIC: Thomson Educational.