8Maria J,Mayan.An introduction to qualitative methods:a training module for students and professional[J].International institute for qualitative methodollgy, 2001 : 10- 14.
9Houldin AD. A qualitative study of caregivers' experiences with newly diagnosed advanced colorectal cancer[J]. Oncol Nurs Forum,2007:323- 330.
10Michelle Byrne. The concept of informed consent in qualitative research [J]. Research Corner.medical research.AORN Journal,2001:9.