This section concerns the author and date components of a citation, this is not a full citation.
Single author name
Spears, Z.K. (2019).
Spears, Z.K., & Booker, M.K. (2019).
3 or more but less than 21 authors
Spears, Z.K., Booker, M.K., Stuckey, D.B., & Single, T.A. (2019).
21 or more authors
When there are 21 or more authors, you use the same format as 3 or more authors until you have included the 20th author. At that point you use an ellipses (instead of the 20th + authors name(s)), followed by the last authors name. Note that there is not an ampersand (&) in this situation.
Lindsey, C., Scurlock, C., Spears, Z., Lindsey, B., Stuckey, D.B., Single, T., Walker, B., Cofer, J., Doe, P.L., Reeves, B., Slater, B.L., Berryman, J.J., Marlowe, I., Hill, B.B. Martin, D., Ware, J., Carmon, A., Legato, C. Booker, M., ... Washington, M.T. (2019)
The date nearly always comes after the author(s) name with only the year listed, and in parentheses, as the above examples show.
No date known for various reasons
In most cases the date is simply the published year, as in the examples above.
Stewart, A. (ca. 1917). Sailboat movie scenes of the early 20th century. Grunderholz Publishing.
Booker, M. (in press). Cataloging anomalies with cucurbits. Iowa Journal of Culinary Librarianship.
Dates will often be written different for different sources which are being cited from . For example, journal publications are generally cited by year of publication only. However, newspaper articles are cited using the day/month/year in this format: 2020, January 29.