While we’re talking about children’s flying saucer books, my husband mentioned today that he remembers one of the first books he read when he was about six or seven, and that was Spaceship Under the Appletree, 1952. He remembered he liked it, and that the cover was green. So here it is:
I also found this version of the cover, but it’s not as nice:
It’s going for a quite a bit too, though not as much as Susie Saucer. Amazon.com has about half a dozen listings for the book, ranging from $31.15, to $94.91.