APA Style
      ERNST, C, H. (2015).
    Factors Driving Social Network Site Usage .
    Springer Fachmedien Wiesbaden:
  Springer Gabler Wiesbaden.
  
MLA Style
      ERNST, Claus-Peter, H..
    "Factors Driving Social Network Site Usage".
    
    Springer Fachmedien Wiesbaden:
  Springer Gabler Wiesbaden,
  2015.
  Text.