Gaya APA
      Kramer, S., Kunkel, D. (2001).
    Hidden worlds : looking through a scientist's microscope .
    New York:
  Houghton Mifflin.
  
Gaya MLA
      Kramer, Stephen., Kunkel, Dennis.
    "Hidden worlds : looking through a scientist's microscope".
    
    New York:
  Houghton Mifflin,
  2001.
  Text.