In 1957, Simpson published this seminal paper defining the risk factors for recurrence following surgical treatment of intracranial meningiomas:
Simpson D (1957): The recurrence of intracranial meningiomas after surgical treatment. J Neurol Neurosurg Psychiatry 20:22–39.
Speizler, R. F. and N. A. Martin (2008). "A proposed grading system for arteriovenous malformations." Journal of Neurosurgery 108(1): 186-193. Landmark paper discusses key features of the Spetzler-Martin grading system