1. Agenesis of isthmus of thyroid gland in adult human cadavers: a case series;Dixit;Cases J,2009
2. [2] Standring S, Herold E, Healy JC, et al. Gray's anatomy. 39th edn. Elsevier Churchill Livingstone 2005:560-4.
3. [3] Moore KL. The developing human: clinically oriented embryology. 4th edn. Toronto: W.B. Saunders. 1988.
4. [4] Moore KL, Persaud TVN. The pharyngeal apparatus. Chap- 10. The developing human clinically oriented embryology. 7th edn. Saunders 2003:215-7.
5. [5] Larsen WJ. Development of head, the neck and the eyes and ears. Chap- 12. Human embryology. 2nd edn. Hong Kong: Churchill Livingstone Inc 1997: p. 371.