The two groups of four numbers are separated by a hyphen which should be included in the search command.
Publishers assign ISBNs to books to simplify and expedite their ordering and purchase.
An ISBN number can often be found on the back of the title page of a book or at the bottom of the back cover, though many older books do not have ISBNs. Sometimes more than one book has the same ISBN, as is frequently the case with books in a series. When searched in this catalog, the hyphens which are often printed as part of these numbers, must be removed and the spaces they occupy closed up.