Citing primary sources properly is important, because the materials found in an archive or special collections repository are often unique and so cannot be referred to elsewhere. Persons trying to locate your sources at a later date will need to know exactly where and how to retrieve them. The particular form of your citation will depend upon the citation style you adhere to (e.g. The Chicago Manual of Style, Modern Language Association, etc.). In general, citations progress from the broadest to the narrowest form of information, or vice versa. The basic elements that should appear in your citation are:
Ex: Special Collections Research Center, Gelman Library, George Washington University, Washington, D.C.
Ex: MS2007 Grace Cavalieri Papers
Ex: Series II: Correspondence
Ex: Box 3 Folder 15 "Submissions, 1972-1973"
Ex: Letter to Mary Ellen Long, January 12, 1970.
When you are at the archives, it is a good idea to note down information from the finding aid or guide to the collection and from labels on the folder and box - even if not all the information is required in the citation itself. Citing primary sources can be tricky. Never hesitate to ask the archivist, curator, librarian, or your professor for assistance. They are there to help you!