[Placebo-controlled study on effectiveness of influenza vaccination?].
Wagner
T A
TA
D000368:Aged; D002986:Clinical Trials as Topic; D006801:Humans; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000517:prevention & control*; D010919:Placebos; D014611:Vaccination
D007252:Influenza Vaccines; D010919:Placebos
Placebo-kontrollierte Untersuchung zur Wirksamkeit der Influenza-Schutzimpfung?