Properly citing your sources is the most important activity in the research process. It is the foundation upon which scholarship is based. Below is an example of an article from an online database (Note/Bibliography style). You need to include the database you used, the vendor url, and the date you viewed the article.
1. Jane Doe, “Incidental Toxins and Deer Mortality in CentralPark,” Pesticides and Urban Ungulates 44, no. 12 (June 2008): 26, http://www.scienceindirect.com/urbscarnage/article2whatrhooves4? (accessed May 5, 2001).
Doe, Jane. “Incidental Toxins and Deer Mortality in Central Park.” Pesticides and Urban Ungulates 44, no. 12 (June 2008): 21-35. http://www.scienceindirect.com/urbscarnage/article2whatrhooves4? (accessed May 5, 2001).
Other examples at the official Turabian Quick Guide from the publisher.
Chicago Style Manual Online. The definitive guide to Chicago style, they literally wrote the book on it! This online version allows convenient access and keyword searching.
Purdue University OWL guide to Chicago/Turabian, including a sample paper
For help with MLA and APA styles, please use the resources here: http://library.kutztown.edu/citations