1. Benisheva T, Clinical trials in the EU and in Bulgaria incl., Bulletin of BACR 1/2008, p 8–13;
2. Clinical Trials.gov is a registry of federally and privately supported clinical trials conducted in the United States and around the world.www.clinicaltrials.gov (access 24.of Oct 2010)
3. Directive 2001/20/EC of the European Parliament and of the Council of 4 April 2001 on the approximation of the laws, regulations and administrative provisions of the Member States relating to the implementation of good clinical practice in the conduct of clinical trials on medicinal products for human use. OJ.2001;L-12:34–44
4. Directive 2001/83/EC of the European Parliament and of the Council of 6 November 2001 on the Community code relating to medicinal products for human use (Consolided version: 30/12/2008).http://www.efgcp.be/html.asp?what=efgcpreport.htm&L1=5&L2=1#report
5. ICREL European forum for good clinical practice.Project final report.