1. Porta M (Editor), Greenland S, Last JM (Associate Editors). A Dictionary of Epidemiology. Fifth edition. Oxford: Oxford University Press, 2008.
2. Miettinen OS. Etiologic study vis-à-vis intervention study. Eur J Epidemiol 2010; 25: 671-5.
3. Miettinen OS. Up from Clinical Epidemiology & EBM. Dordrecht: Springer, 2011.
4. Fletcher RH, Fletcher SN. Clinical Epidemiology. The Essentials. Fourth edition. Philadelphia: Lippincott Williams & Wilkins, 2005; pp. 2-3.
5. Hulley SB et alii. Designing Clinical Research. Third edition. Philadelphia: Lippincott Williams & Wilkins, 2007; p. xiii.