what is the notion for subsequent multiple authors in a citation

You didn't say whether you needed MLA or APA format. This site will give you both.

http://www.geocities.com/researchguide/styleguides.html

I needed it for APA Format

This site has the APA .... good examples.

When citing a source with multiple authors, there are different ways to format the citation depending on the citation style you are using. One commonly used citation style is the American Psychological Association (APA) style. In APA style, the format for citing multiple authors in a citation is as follows:

For in-text citations:
- For sources with two authors, include both authors' last names joined by an ampersand (&) in parentheses. For example: (Smith & Johnson, 2021)
- For sources with three or more authors, include the first author's last name followed by "et al." (which stands for "and others") in parentheses. For example: (Smith et al., 2021)

For the reference list:
- List all authors' last names and initials (separated by commas) up to and including the sixth author. After the sixth author's name, use an ellipsis (...) and then the last author's name. For example: Smith, J. D., Johnson, L. M., Anderson, K. P., ... Brown, R. A.

It's important to note that different citation styles may have slightly different rules for formatting multiple authors. Therefore, always consult the specific style guide or manual for the citation style you are using to ensure accurate formatting.