Sometimes books are published as part of a series or annually. These are books, but they're not monographs.

Examples of annuals are directories or guides which are updated yearly: Who's Who in Canada, The Statesman's Yearbook, The Environmental Directory. The library might have a "standing order" to automatically purchase each new version or it might update only occasionally.

Books which are part of a series may have a unique title for each book, as well as a series title. For example, we have 70 books from the "Cambridge Classical Studies" series, each with its own title. There is not always a regular schedule for new publications in a series and the library doesn't necessarily purchase every item in the series.

TOPCAT records include both the individual title of the book and the series to which it belongs, so we can find these items under either title.