Critical appraisal of epidemiological studies and clinical trials /
Elwood, J. Mark.
Elwood, J. Mark.Causal relationships in medicine.
Oxford : Oxford University Press,
1998.
Rev. ed. of: Causal relationships in medicine / J. Mark Elwood. 1988
Includes bibliographical references and index
Epidemiology
Clinical trials.
Epidemiology
Clinical trials
Diseases