Evaluation of Echinacea for the prevention and treatment of the common cold: a meta-analysis - Shah, S A; Sander, S; White, C M; Rinaldi, M; Coleman, C I (Lancet Infect Dis, 2007)
Erratum in: Lancet Infect Dis 2007; 7: 580 Erratum in: Lancet Infect Dis 2007; 7: 580