APA Style

Roper, N. et al (1991). The elements of nursing: a model for nursing based on a model of living (Third Edition). London: Chrchill Lnivingsone.

MLA Style

Roper, Nancy. et al. "The elements of nursing: a model for nursing based on a model of living". Third Edition London: Chrchill Lnivingsone, 1991. Text.