done. fix secondary authors (was: adjust format)

[Miriam]

The publisher lists it as a hardcover format for that ISBN

https://www.harpercollins.com/product...

[Sandra]

Looking at Abebooks, of 73 books listed only 6 were hardcovers & 60 odd were paperbacks, the rest didn't say. All were for that isbn.

So you're both correct. The paperbacks were all 2012 with one 2013. The hardcovers mostly seemed to be 2016, so if an alternative edition was added the hardcover would keep the isbn.

[Sandra]

I was intrigued, though I have seen many publishers over the years re-use isbns and have inadequate info on their book pages.

[Sandra]

Done & added Sheryl Crow to the 2 editions listed on worldcat.