Kristoffersen, E. S., Lundqvist, C., Aaseth, K., Grande, R. B., & Russell, M. B. (2013). Management of secondary chronic headache in the general population: The Akershus study of chronic headache. Springer.

Kristoffersen, Espen Saxhaug, Christofer Lundqvist, Kjersti Aaseth, Ragnhild Berling Grande, and Michael Bjørn Russell. Management of Secondary Chronic Headache in the General Population: The Akershus Study of Chronic Headache. Springer, 2013.

Kristoffersen, Espen Saxhaug, et al. Management of Secondary Chronic Headache in the General Population: The Akershus Study of Chronic Headache. Springer, 2013.