Gaya APA
Friis, R, H., Selleres, T, A. (2009).
Epidemiology for Public Healt Practice (fourth edition).
London:
Jones and Bartlett Publishers, INC.
Gaya MLA
Friis, Robert, H.., Selleres, Thomas, A..
"Epidemiology for Public Healt Practice".
fourth edition
London:
Jones and Bartlett Publishers, INC,
2009.
Text.