Polit, Denise F. Nursing research : principles and methods / Denise F. Polit, Bernadette P. Hungler. - 4th ed. - Philadelphia : Lippincott, c1991. - xiv, 697 p. : ill. ; 24 cm. Includes bibliographical references and indexes. ISBN: 0397548206 LCCN: 90013624 Subjects--Topical Terms: Nursing--Research--Methodology.Nursing Research. LC Class. No.: RT81.5 / .P76 1991 Dewey Class. No.: 610.73/072 National Library of Medicine Call No.: WY 20.5 P769n