Gaya APA
      R.David, F. (2009).
    Strategic Management Concepts (Twelfth Edition).
    United State of America:
  Pearson Prentice Hall.
  
Gaya MLA
      R.David, Fred.
    "Strategic Management Concepts".
    Twelfth Edition
    United State of America:
  Pearson Prentice Hall,
  2009.
  Text.