If an article that has been accessed online does not have a DOI, then the citation ends with the URL of the journal's website, even if you actually retrieved the article through a database.
Template:
Author, A. A. (Year). Title of article: Subtitle of article. Title of Journal, volume (issue), page range. Retrieved from http://...
Example:
Sidani, S. (2003). Enhancing the evaluation of nursing care effectiveness. Canadian Journal of Nursing Research, 35(3), 26-38. Retrieved from http://cjnr.mcgill.ca
If an article is only available through a database (i.e. when the journal is no longer being published and so does not have a website), give the name of the database and the accession number of the article (or whatever unique number the database has assigned to the article).
Example:
Wysong, S., Kissel, G. J., & Beldona, S. (2008). "Made in China”: The effect of country association on a brand personality. American International College Journal Of Business, 17(1), 54-54. Retrieved from Business Source Complete. Accession number: 36786886.