Polit, Denise F. Nursing research : principles and methods : study guide / by Denise F. Polit, Bernadette P. Hungler. - 4th ed. - Philadelphia, N.Y. : J.B. Lippincott, 1991. - viii, 241 p. Contents : The scientific research process--Preliminary research steps. ISBN: 0397548214 Subjects--Topical Terms: Nursing research.