This paper reviews rules governing the use by judges in United States courts of their personal knowledge - as distinguished from that supplied by the parties in the adjudication of a civil case, whether of the particular facts out of which the dispute arises, or of general information with which the particular facts must be processed, or of law which is to be applied to the particular facts.
William B. Fisch, Judicial Knowledge, 34 Am. J. Comp. L. Supp. 237 (1986)