The new books are at the front on the left; the stories not written by Ruth Chew are at the front on the right, and the translations are the leftmost column (those black ones with the glittery spines are all Japanese). The rest are all hardcovers and paperbacks from different years representing Ruth Chew’s 29 stories for children in English spanning the 30 years from 1969 to 1999.
Most of the books in the collection are distinct in some detail; many of the paperback books are similar but have different ISBNs, slightly different covers or cover prices, or have a different print run encoded on the copyright page.
Sometimes it’s tricky to buy an exact edition because online booksellers will list a book for sale under the ISBN of a slightly different edition. This happens especially in the case of the older books, which don’t have ISBNs of their own!
If you’re interested in collecting Ruth Chew books, too, have a look at the information for collectors.