How do I list a reference for an article that does not have a DOI?
Instructions differ between APA 6th Edition and APA 7th Edition.
When citing by 7th Edition standards, if an article sourced from most academic research databases does not have a DOI, simply end the citation without a DOI or URL. A URL is only included for databases that publish limited circulation or proprietary works. See the 7th Edition Manual, section 9.34, at the Ask a Librarian desk for detailed information on this topic.
When citing by 6th Edition standards, if no DOI is listed, include the URL of the journal home page as the source of the article.
Where do I find the URL of the publisher?
There is no standard format for the listing of the publisher URL. The journal homepage URL can often be found by clicking on the hyperlinked title of the publication in Source field of the article citation.
This will take you to a page with information about the publication, which often includes a URL for the publisher.
Method for citing:
O'Shea, L. (2002). An economic approach to reducing water pollution: Point and diffuse sources. Science of the Total Environment, 282-283, 49. http://www.elsevier.com/
If not listed, the publisher URL can be found by searching the title of the publication on Google.