1. 1. European Parliament and Council of the European Union. Regulation (EC) No 141/2000 of the European Parliament and of the Council of 16 December 1999 on orphan medicinal products. Official Journal of the European Communities. 2000; 22.1.2000.
2. 2. US Code of Federal Regulations (CFR) Title 21 Food and Drugs Part 316 Orphan Drugs.
3. 3. Center for Drug Evaluation and Research (CDER), Center for Biologics Evaluation and Research (CBER), Food and Drug Administration. Guidance for Industry: Qualifying for Pediatric Exclusivity Under Section 505A of the Federal Food, Drug, and Cosmetic Act. http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM080558.pdf (accessed January 30, 2014).
4. 4. Hall AK. The practicalities of clinical development of drugs for rare diseases. In: Rare Diseases: Challenges and Opportunities for Social Entrepreneurs (Sireau N, ed.). Greenleaf Publishing, Sheffield, UK, 2013; pp.62-86.
5. 5. Commission of the European Communities (2000). Commission Regulation (EC) No 847/2000 of 27 April 2000 laying down the provisions for implementation of the criteria for designation of a medicinal product as an orphan medicinal product and definitions of the concepts "similar medicinal product" and "clinical superiority". Official Journal of the European Communities. 2000; 28.4.2000.