Diagnosing the Severe Headache
Neurol 44:S6-S12, Dalessio,D.J., 1994
Headache as the Only Neurological Sign of Cerebral Venous Thrombosis:A Series of 17 Cases
JNNP 76:1084-1087,1043, Cumurciuc,R.,et al, 2005
Sphenoid Sinusitis
NEJM 309:1149-1154, Lew,D.,et al, 1983