DOIs are Document Object Identifiers that are unique to each specific article. From the article you want to provide access:
Here is an example with all of the parts:
Rutgers, The State University of New Jersey, an equal access/equal opportunity institution. Individuals with disabilities are encouraged to direct suggestions, comments, or complaints concerning any accessibility issues with Rutgers web sites to: firstname.lastname@example.org or complete the Report Accessibility Barrier / Provide Feedback Form.