Polit, Denise F. <br/><br/>
Essentials of nursing research :  appraising evidence for nursing practice / 
Denise F. Polit, Cheryl Tatano Beck. 
 - 8th ed. 
 - Philadelphia :  Wolters Kluwer Health /Lippincott Williams & Wilkins,  c2014 . 
 - xviii, 493 p. :  ill. (chiefly col.) ;  26 cm.