Polit, Denise F. Essentials of nursing research : methods, appraisal, and utilization / byDenise F. Polit, Cheryl Tatano Beck. - 6th ed. - Philadelphia : Lippincott Williams & Wilkins, 2006. - xii, 554 p. : ill. ; 23 cm. Includes bibliographical references and index. ISBN: 0781749727 (alk. paper) Subjects--Topical Terms: Nursing --Research.Nursing Research. LC Class. No.: RT 81.5 POL 2006