A Digital object identifier, also known as a DOI, is an alphanumeric string assigned to an article by a publisher to provide a persistent link for online access.
Some of the citing examples provided in the links below include:
Not all dates will look the same.
No dates: "I can't find any date information. What do I do?"
Sometimes a source may not have a date, and that is often true for information found on a website. In those cases, you should use "n.d." (short for "No date") in place of the date. Example: Smith (n.d.)
An adapted and abbreviated style for in-text citing of sources for a table or chart is shown in the image below. Include the author's last name (or name of organization) and the year. If the graphic includes information from multiple sources, include an in-text citation for each in alphabetical order, separated by a semi-colon. The References page at the end of your paper should include the full-text citation for the sources cited under the graphic.