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Secondary sources are works that provide commentary on historical events. They are typically written by scholars and incorporate primary source documentation in order to analyze and interpret past events. Most historians publish their work in books. So, for many topics in history, your best starting point is a good recent scholarly book.
To find historiographic essays, books, and articles, consult our Online Catalog, WorldCat and journal article databases (such as Historical Abstracts & Full Text), by using "historiography" is a Subject term.
To find book-length bibliographies on a topic in library catalogs, use the advanced search to look for "bibliography" as a Subject and your topic as a Keyword.
History as a general subject can be found in the C, D, and F Library of Congress (LC) Call Number ranges in MSU Libraries. You can go to the LC Class lists and click on the relevant subclass for a more in-depth call number outline.
While the main subject of "History" is classified as in Classes C, D, E and F, every discipline has its own history, and therefore may be classified within that discipline. For instance, agriculture would fall under Class S; the history of general agriculture would fall under subclass S419-482. There is also a separate subclass for plant culture history, animal culture history, etc.
MSU has a full range of databases to search for journal articles. These are a few to get you started. See below for additional resources.