Steen Østergaard, Michael Bjørn Russell, Lars Bendtsen, Jes Olesen
Ãstergaard S, Russell M B, Bendtsen L, Olesen J.
Comparison of first degree relatives and spouses of people with chronic tension headache
BMJ 1997; 314 :1092
doi:10.1136/bmj.314.7087.1092