Clinical Reasoning: A 33-year-old Woman with Severe Postpartum Occipital Headaches
Neurol 78:366-369, Maalouf,N. and Harik,S.I., 2012
Severe Headaches, When to Worry, What To Do
Postgrad Med 83:164-180, Drexler,E.D., 1990
When the Headache is Ominous
Emerg Med Nov 1973, pp 87., Joynt,R., 1973