Kristoffersen, E. S., Aaseth, K., Grande, R. B., Lundqvist, C., & Russell, M. B. (2018). Psychological distress, neuroticism and disability associated with secondary chronic headache in the general population – the Akershus study of chronic headache. J Headache Pain.

Kristoffersen, Espen Saxhaug, Kjersti Aaseth, Ragnhild Berling Grande, Christofer Lundqvist, e Michael Bjørn Russell. "Psychological Distress, Neuroticism and Disability Associated With Secondary Chronic Headache in the General Population – the Akershus Study of Chronic Headache." J Headache Pain 2018.

Kristoffersen, Espen Saxhaug, et al. "Psychological Distress, Neuroticism and Disability Associated With Secondary Chronic Headache in the General Population – the Akershus Study of Chronic Headache." J Headache Pain 2018.