The Bibliographic Search ISBN (External) page in the cataloguing menu is a search page for finding bibliographic records from a variety of external databases by their ISBN. This type of search will bring accurate results to the exact title you are looking for unlike a keyword search.
Each database/institution you wish to search must be ticked and any institutions/databases you wish to omit from searching must be unticked before you begin your search. There is a select all button for the whole list, as with each individual subheading which can be used to widen or narrow your search.
The process for searching and copying records within this search page is the same as the Bibliographic Search (External) and you can view the process for this there, the only difference is that instead of a keyword search you will be searching using one or multiple ISBNs.
If you are searching using multiple ISBNs press enter after every ISBN to place the next on a new line as shown below: