Provided by SU Libraries: EasyBib Academic Edition
You always have the most control over the accuracy of your citations when you do it by hand using the selected style manual (below).
Purdue OWL: Formatting in ASA - references and in-text citation help
American Sociological Association - quick tips for ASA style as a pdf
From the Purdue OWL site, for APA:
Point readers to raw data by providing a Web address (use "Retrieved from") or a general place that houses data sets on the site (use "Available from").
United States Department of Housing and Urban Development. (2008). Indiana income limits [Data file]. Retrieved from http://www.huduser.org/Datasets/IL/IL08/in_fy2008.pdf