Libraries collect and preserve the graphic records of human experience.1 Not every experience is documented, and not every documented experience is collected and preserved. How, then, can you know what part of the historical record remains for you to study? Reference sources are your map to the graphic records of human experience.

Even if every human experience hasn't been documented, and every document hasn't been preserved, there remains a plethora of sources available for the historian to study. Here at the University of Illinois Library, you have access to over 14 million printed books, 9 million microforms, 120,000 periodicals, 148,000 sound recordings, 1 million audiovisual resources, 280,000 e-books, 29,000 cubic feet of archival records, 3 terabytes of electronic records, and 650,000 maps—that's over 24 million potential primary sources for your research. Reference sources are your map to the Library's collections.

1. Jesse H. Shera, The Foundations of Education for Librarianship (New York: Becker and Hayes, 1972): 193.