Some reports, books, theses, and similar works can be part of series. This is usually indicated on the cover or one of the first pages. Place the series title in parentheses directly after the title. The parentheses and series title should not be in italics. If the series has a number, include it as it is written in the publication.
Example:
Timpe-Laughlin, V., Roters, B., & Butler, Y. G. (2024). Exploring the Idea of Task in the Context of the Young Language Learner Classroom (ETS Research Report Series). https://onlinelibrary.wiley.com/doi/abs/10.1002/ets2.12389
For reports: Enter series title in the field Report number.
For books: Not possible in EndNote. Edit manually.
For reports: Add series title in the field Series Title.
For books: Use the field Series.