As explained previously, libraries collect and preserve the graphic records of human experience.1 However, not every experience is documented, and not every documented experience is collected and preserved, and you can how much more this is true of groups that have been historically persecuted. 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.
Use reference sources for factual information like the date the Defense of Marriage Act was signed into law, or where in the United States Statutes at Large to find it. You can also use them to find more complex information, like marriage law in Islam. They often include bibliographies, making them profitable places to begin a research project.
Encyclopedias attempt to summarize, as concisely as possible, the state of knowledge in a field of inquiry. Use encyclopedias to find background information on your topic, and to familiarize yourself with what is already known on the topic. A good encyclopedia can be a valuable starting point for your research, and often contains recommendations for additional reading.
There are many encyclopedias that compile knowledge about a specific nation or region. For example, Encyclopedia of Latin American History and Culture, Encyclopaedia Iranica, or Encyclopedia of the Third Reich. These encyclopedias will often include entries on marriage, divorce, and the family--they make excellent places to begin exploring possible topics. We've included a few of the more substantial titles in the list below.
Three online reference collections that students often find useful are:
Historical Aspects of the Family
Contemporary and Legal Aspects of the Family
Religious Aspects of the Family
Gender and the Family
A bibliography is, in its most literal sense, a list of books. Many students are familiar with bibliographies from writing research papers, where a list of works cited is sometimes called a bibliography. In libraries, bibliographies serve an additional, important function in helping patrons identify books, journal articles, and other library resources. These bibliographies are usually centered on sources about a particular subject, and are often book-length themselves. Some bibliographies run to several volumes. For more information on bibliographies, please see our guide to Bibliography and Historical Research.
A catalog is similar to a bibliography with the difference being that a catalog lists books and other resources available for use or purchase at a specific place, or from a specific person or organization. Examples are library catalogs, catalogs of private collections, and booksellers' catalogs.
Statistics, like most information, are created to perform specific work at a specific place and time. Most of the statistical sources you will find in libraries are either government documents, or based on statistics collected by governments. Non-governmental organizations (NGOs) like the United Nations, the World Health Organization, Human Rights Watch, and Amnesty International also collect and publish statistical reports that can be found in libraries.
Some of the most interesting statistics, however, are commissioned by for-profit companies and produced for the exclusive use of those companies. Libraries typically are not able to collect these reports because the reports are never published, and obviously the statistics are supposed to give the commissioning company a competitive advantage, which would be forfeited if those statistical data were made generally available. Here's an example of a page from a six volume statistical appendix that accompanied a report called "The New Bank Customer". The report was prepared in 1971 by a market research firm called Institute for Motivational Research for six major U.S. banks. The market research firm collected statistical data on bank customers, and then used those data to develop a typology of banking customers: Money Puritans, Money Realists, and Money Adventurers. These data were then segmented by age, gender, education, marital status, occupation, income, number of children, and city of residence.
Image credit: "The New Bank Customer: A Motivational Research Study - [Statistical] Appendix, Vol. II" (Report, Hagley Museum and Library, 1971).
1. Jesse H. Shera, The Foundations of Education for Librarianship (New York: Becker and Hayes, 1972): 193.