Unable to find supposed duplicate copy

Not sure if this actually belongs here but maybe someone could shed light on it. I just added this book:

https://www.librarything.com/work/509785/book/211070280

and I get the message that there is another copy of it in Your Books. I see nothing peculiar about the Book or Work pages. There is nothing corresponding to this book when I search on author or title. I deleted the ISBN because this is an older edition that did not have ISBN. The book does not appear on the Work Duplicates page either. Just out of curiosity, is there a duplicate and how would one go about finding it, if it does not appear in the library search ?

Thanks for any help

When you go here

https://www.librarything.com/stats/MEMBERNAME/workdups

does the book show up?

To get to that url:
Click on your profile name
Click on charts & graphs
Scroll to the bottom, click Odds & Ends
Click Work Duplicates

There was a combination issue:
Your copy of The wheel of life and death : a practical and spiritual guide by Philip Kapleau was hiding in this work: The wheel of life : the autobiography of a Western Buddhist by John Blofeld instead of being with the other copies of Kapleau's book. So when you added your copy of the latter, the system told you that you already have it.

I moved it out and recombined it where it needs to be :)
The easiest way to find these is to look at the bottom of the box on the link you posted or use the duplicates finder under your Graphs and charts.

PS: >2 lesmel: beat me to explaining where to look for these duplicates :)

Terrific; thanks for the help. Someday I will figure out how to do these on my own !