1. Balla J, Iansek R: Headaches arising from disorders of the cervical spine. In Headache: Problems in Diagnosis and Management. Edited by Hopkins A. Philadelphia: Saunders; 1988:241–267.
2. Radanov BP, Sturzenegger M, Di Stefano G: Long-term outcome after whiplash injury. Medicine 1995, 74:281–297.
3. Sjaastad O, Fredriksen TA, Båtnes J, et al.: Whiplash in individuals with known pre-accident, clinical neck status. J Headache Pain 2006, 7:9–20.
4. Headache Classification Committee of the International Headache Society: The International Classification of Headache Disorders, 2nd edn. Cephalalgia 2004, 24(Suppl 1):1–160.
5. Pereira-Monteiro JM: Cefaleias. Estudo Epidemiologico e Clinico de uma Populacao Urbana [thesis]. Porto, Portugal; 1995.