1. Merck Manual of Diagnosis and Therapy;Porter,2011
2. High Yield Microbiology and Infectious Diseases;Hawley,2006
3. Harrison's Principle of Internal Medicine;Fauci,2018
4. Wolters Kluwer. UpToDate online. Available from: http://www.UpToDate.com.
5. Wikipedia online. Available from: http://www.wikipedia.com.