Polit, Denise F. <br/><br/>
Essentials of nursing research :  appraising evidence for nursing practice / 
Denise F. Polit ; Cheryl Tatano Beck. 
 - 7th ed. 
 - Philadelphia :  Wolters Kluwer Health/Lippincott Williams & Wilkins,  2010. 
 - xiv, 610 p. :  col. ill. ;  24 cm.