Primary vs. Secondary Sources

Primary sources: Original writings, research or documentation of an event from the time that it occurred. Examples of primary sources include manuscripts, interviews, diaries, letters, and newspaper articles (written at the time of an event).
Secondary sources: Information written about a primary source. Examples of secondary sources include literature reviews and literary criticism.

The Rocky Horror Picture Show. Dir. Jim Sharman. Perf. Tim Curry, Richard O'Brian, Susan Sarandon, and Barry Bostwick. 1975. DVD. Twentienth Century Fox Home Entertainment, 2002. {Movie}
The Rocky Horror Show: Theatrical Program. Davis: University of California, 2005. {Program}
O'Brian, Richard. The Rocky Horror Show: Musical. London: S. French, 1983. {Stage Play, Music & Lyrics}
Kinkade, Patrick T. "Toward a Sociology of Cult Films: Reading Rocky Horror." The Sociological Quarterly Summer 1992: 191-209. {Article}
Riggs, Lee. Personal Interview. 7 Mar. 2005. {Interview with Cast Member}

Michaels, Scott, and David Evans. Rocky Horror: From Concept to Cult. London:Sanctuary, 2002. {Book}
Barnes, Clive. "Stage: A Flashy 'Rocky Horror Show' (Review)." New York Times 11 March 1975: 26. {Stage Review Article}