See section 7.10, Archival Documents and Collections. In particular, rule #72 for historical publication of limited circulation (p.214) is appropriate for pamphlets or brochures.
|All information and page number references are based on the 6th edition of the Publication Manual of the American Psychological Association (2009/10).|
Need a copy of the Publication Manual? Click here for details. See Also: APA Style Guide to Electronic References, Sixth Edition