The Test digit is base eleven, and might be an integer amongst 0 and 9, or an 'X'. The method for 13-digit ISBNs isn't appropriate with SBNs and can, generally speaking, give another Test digit through the corresponding ten-digit ISBN, so would not deliver the same safety towards transposition. https://deepodirectory.com/listings13315079/top-guidelines-of-gr%C3%BAa-para-construcci%C3%B3n-y-mudanzas-sevilla