[Link goes to library catalog.] The sixth edition (2010) of the official guide is available at W&L only in printed form -- no online access.
Copies in Leyburn Permanent Reserve and Science Reference @ BF 76.7 .P83 2010
APA Style is used most often in the social sciences.
Official APA guide is adapted from the sixth edition of the Publication Manual of the American Psychological Association and intended to "show how to format references for a broad range of electronic sources," covering such elements as URL's and DOI's. (You need to login with your W&L ID/password.)
Other Guides to APA Style
These guides are "unofficial," but highly regarded. The first item listed here, sometimes referred to simply as the "Hacker site," is a particularly easy-to-use online guide to APA citation formatting.
[Link goes to library catalog.] Available only in printed form, with copies shelved in Leyburn Permanent Reserve and Science Reference @ BF 76.7 .C66 2010. This is the "short version" of the full Publication Manual, with samples of bibliographical entries in "Reference Examples" on pp. 209-255.
Citing Government Sources Using APA Style -- Advice and Examples
For additional help with citing government resources using APA Style, see this brief guide: