Adding Subject Headers?

Hello, I'm new to LT. I really like the "subject" feature on the site, but I've noticed some of my books don't have these nifty little descriptors. Unlike other information about my books, I haven't found a way to add this information to books which don't have it - not in the main page, works page, edit my book, double-clicking the empty space on the book's entry on my "Your books" view, etc. Is there some way I can get this info on works that are missing it?

From my understanding of the site so far, the following information might be relevant. Some of these books are books that other members of the site also own, and some are manual entries which I have separated from the global work (for purposes of dividing volumes in a set into separate entries and grouping them in a series without messing about with the global version, which is listed all volumes in a single entry and therefore wouldn't be in a "series" with itself).

So, some books are books other users have, and some I effectively own the only "edition" of on the site, if that would in any way affect how I went about seeking subjects for these entries.

Thank you for your help!

You cannot add subject headings. They can only be added from the source. If you want subject headings you need to use library sources that have them, particularly Library of Congress. Certainly NOT Amazon.

Multi volume sets can be entered as series, and if different single volumes are mixed into the work, they need to be sorted out. But we can't help if we don't know what work you are talking about.

If you click on the ? in the right corner of the search result, it will show all data to be imported and you can see whether it has subject headings. They are at the every bottom of the list. Most libraries have them if they are available at all.

>3 SandraArdnas:
This is very helpful, I didn't notice this feature. Thank you!

>2 MarthaJeanne:
I did not know this! I was looking at Library of Congress first, then Overcat, and if neither had a book I went to Amazon, now I know not to do that.

Here is the forum post where I go into more depth about the multi-volume series. https://www.librarything.com/topic/360909#n8538999
Unfortunately it seems that I may just have to keep that series without subject headings, then. Not what I really wanted, but it's more important to me that the separate volumes are in a series together and not grouped under one entry.

Thank you for your help!