World health Organization. (2001). Health research methodology: A guide for training in research methodology (2nd- ed.). World Health organization.
Chicago-Zitierstil (17. Ausg.)World health Organization. Health Research Methodology: A Guide for Training in Research Methodology. 2nd- ed. Manila: World Health organization, 2001.
MLA-Zitierstil (8. Ausg.)World health Organization. Health Research Methodology: A Guide for Training in Research Methodology. 2nd- ed. World Health organization, 2001.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.