Both of these titles of little golden books are out of print. That is what the publisher would tell you. Both titles are available in the used book market.

I searched for Puff the Blue Kitten for many decades, not knowing its title. It was only when I found it on EBay--luckily the seller posted several photos of the illustrations--that I recognized it and bought it immediately. You can just add it to your searches on EBay (search "Puff the Blue Kitten" or Pierre Probst, the author, and no doubt you'll be able to win a copy. I bought an Australian edition (similar to the U.S. edition). If you buy the French version (it's under the series title Les Albums Roses), you can get a couple more gorgeously illustrated pages. I adore this book and was beyond giddy once I had my hands on it.