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Sjaastad O, Stovner LJ.Sjaastad O, et al. Among authors: stovner lj.Headache. 1993 Jul-Aug;33(7):372-5. doi: 10.1111/j.1526-4610.1993.hed3307372.x.Headache. 1993.PMID: 8376097No abstract available.