Citing an article you got full-text from an online database needs to have additional information at the end of the citation, which shows where you retrieved it. This is so that your professor or anyone who wants to track down the article you cited can know where to find it.

Online databases include ones such as Academic Search Premier, Business Source Premier, Expanded Academic ASAP, JSTOR, PsycINFO, Education Full Text, Library Literature & Information Science Full Text and so on that are offered through the Library.

Example
Hodapp, William F. "Minerva's Owl in Charles d'Orleans's English Poems: A
Mythographic Note on Line 4765." ANQ 9.1 (1996): 3-7. Expanded Academic ASAP.
Thomson Gale. Coll. of St. Scholastica Lib.,Duluth, MN. 11 Jan. 2007 <www.gale.com>.

The first part of the citation will be the same as what you would do for a print article. See the appropriate MLA citation page for this part. (Newspaper, Magazine, Journal)

The second part of the citation includes information on where you found the article including:

Database
The name of the online database you located the article in. Underline and end with a period - Expanded Academic ASAP.

Database supplier
The name of the company that creates the database. End with a period - Thomson Gale.
Use the following list to find the supplier for the database you used:
Database = Supplier
ABELL/Literature Online = Proquest
Academic Search Premier = Ebsco
Access World News & America's Newspapers = Newsbank
American Indian History Online = Facts on File
Business Source Premier = Ebsco
AP Science Direct/Elsevier = Elsevier
CINAHL = Ebsco
Ebsco MegaFILE = Ebsco
Expanded Academic ASAP = Thomson Gale
JSTOR = JSTOR
PsycINFO = Ovid
Education Full Text = H. W. Wilson
Library Literature & Information Science = H. W. Wilson
Periodicals Archive Online = Proquest
Proquest Newsstand Complete = Proquest
*For any other database, look at its copyright or publication information or ask a librarian.

Library which provides access to database
Access to online databases such as Expanded Academic ASAP are leased by libraries. Indicate the name of the library which provided you with access. If a college library, abbreviate "college." End with a period - Coll. of St. Scholastica Lib., Duluth, MN.

Access date
Day, month, & year you accessed (viewed) the article. Use the proper abbreviations for months - 11 Jan. 2007

Web site URL of database supplier
Place in angle brackets (carrot marks). End citation with a period - <www.gale.com>.
Use the following list to find the supplier for the database you used:
Supplier URL
Facts on File http://www.fofweb.com
Ebsco <http://epnet.com>
Elsevier <http://www.sciencedirect.com/>
H. W. Wilson <http://www.hwwilson.com/>
JSTOR < http://www.jstor.org/>
Newsbank <http://infoweb.newsbank.com/>
Ovid <http://gateway.ovid.com/>
Proquest <http://www.il.proquest.com/>
Thomson Gale <www.gale.com>
*For any other database, look for its homepage address or ask a librarian

[The above information is based on p. 229 of the MLA Handbook for Writers of Research Papers, 6th edition]