1. The Merck Manual-Fifteenth edition, 1987; 17: 2196–2197.
2. Gwaltney JM. Acute sinusitis in adults. Am J Otolaryngol, 1983; 4: 422–423.
3. Weinstein L. Diseases of the upper respiratory tract infections. In «Harrison’s Principles of Internal Medicine», 11th edition, 212, USA McGraw-Hill Co, 1987; 1113–1114.
4. Ekedahl C. Akute Sinusitis bei Erwachsenen Infection, 1987; 15: Suppl 3.
5. Ludwig E, Graber E, Arr M. Doxycycline in clinical practice. Ther Hung, 1987; 35, 4: 190–5.