I have an older book that seems to have a 12 digit SBN. It tells me the number is invalid. I looked up converting SBN to ISBN, but apparently the SBN is supposed to be 9 digits and you add a 0 to make it 10 but that doesn’t work either.
Ray Bradbury - Fahrenheit 451 345227611125
photos of the book: https://imgur.com/a/tvhk2Is
I did a quick internet search of your title and SBN and found this entry on Abe books https://www.abebooks.co.uk/9780345227614/Fahrenheit-451-Ray-Bradbury-0345227611/plp So, for troublesome books, try the Internet. Abebooks also gives the ISBN 13, which can be found from CLZ, albeit with a different cover.