Zwart, S., Sachs, A. P. E., Ruijs, G. J. H. M., Gubbels, J. W., Hoes, A. W., & de Melker, R. A. (2000). Penicillin for acute sore throat: Randomised double blind trial of seven days versus three days treatment or placebo in adults. British Medical Journal.

Zwart, Sjoerd, Alfred P E. Sachs, Gijs J H M. Ruijs, Jan W. Gubbels, Arno W. Hoes, und Ruut A. de Melker. Penicillin for Acute Sore Throat: Randomised Double Blind Trial of Seven Days Versus Three Days Treatment or Placebo in Adults. British Medical Journal, 2000.

Zwart, Sjoerd, et al. Penicillin for Acute Sore Throat: Randomised Double Blind Trial of Seven Days Versus Three Days Treatment or Placebo in Adults. British Medical Journal, 2000.