1. 1. HH Hazen . Syphilis. A treatise on etiology, pathology, diagnosis, prognosis, prophylaxis, and treatment . St. Louis: Mosby, 1921 : 581 .
2. 2. L. Thompson, Syphilis . Philadelphia: Lea & Febiger, 1916 : 193 .
3. The Treatment of Syphilis in the Salvarsan Era