Children's book: Karlsson on the roof

Lillebror lives in a flat in a Stockholm building and what she wants most in the world is to have a dog. Karlsson lives on the roof, in a little house hidden behind the big chimney. He is, by his own account, handsome, intelligent, perfectly plump, and in the prime of his life. In addition, it has a small propeller on its back, which is why it can fly. Lillebror adores Karlsson, but his mother, father, older brothers and friends are convinced that Karlsson is a Lillebror invention. Karlsson laughs and says: "They really are an invention." As soon as Karlsson appeared in Lillebror's life, everything became fantastic and exciting.