The crossover design for migraine preventives: an analyses of four randomized placebo-controlled trials

by Astrid Bjørke Jenssen, Lars Jacob Stovner, Erling Tronvik, Trond Sand, Grethe Helde, Gøril Bruvik Gravdahl, Knut Hagen
Published 2019-12-01

The epidemiology of headache disorders: a face-to-face interview of participants in HUNT4

by Knut Hagen, Anders Nikolai Åsberg, Benjamin L. Uhlig, Erling Tronvik, Eiliv Brenner, Marit Stjern, Grethe Helde, Gøril Bruvik Gravdahl, Trond Sand
Published 2018-03-01