↑Minnesota Department of Health. Minnesota Birth Index, 1935-2002 [database on-line]. Provo, UT, USA: The Generations Network, Inc., 2004.
↑"Based on the original Dungeons & Dragons rules created by E. Gary Gygax and Dave Arneson."—Monte Cook, Jonathan Tweet, et Skip Williams, Dungeons & Dragons Player's Handbook (Renton, Washington: Wizards of the Coast, 2000), p. 2.