The
Find Duplicates plugin allows you to compare books in two different libraries. In the library your are doing the comparison from, all duplicates books will be marked, so that you can do with them as you please.
The advantage to that approach, is that unlike comparing lists of books, the plugin have algorithms to allow you to match books that have similar—but not identical—titles and authors. For example if the following two books are in separate libraries they will be matched even though author name does match letter to letter:
Code:
Philip K. Dick - Total Recall
Code:
Philip Dick - Total Recall