Roberts, C. L., Raynes-Greenow, C. H., Nassar, N., Trevena, L., & McCaffery, K. (2004). Protocol for a randomised controlled trial of a decision aid for the management of pain in labour and childbirth [ISRCTN52287533]. BioMed Central.

Roberts, Christine L., Camille H. Raynes-Greenow, Natasha Nassar, Lyndal Trevena, و Kirsten McCaffery. Protocol for a Randomised Controlled Trial of a Decision Aid for the Management of Pain in Labour and Childbirth [ISRCTN52287533]. BioMed Central, 2004.

Roberts, Christine L., et al. Protocol for a Randomised Controlled Trial of a Decision Aid for the Management of Pain in Labour and Childbirth [ISRCTN52287533]. BioMed Central, 2004.