The editor’s introduction to ‘Les enfants du voyage” in the French magazine  Fiction #182, February 1969, p82-97:
“Science fiction is never short of new talents and unknown names are constantly coming to the forefront. Let’s admit that it took us a while to spot that of Dean R. Koontz: when we are used to trusting established authors, a story signed with a name like that hardly makes us want to read it. Until the day we came across by chance, in our selections of American texts, on The psychedelic children (the short story that you will read below). From the outset, a tone was imposed which was that of a writer worthy of attention. We therefore retained this text. At the same time, we noted that Dean R. Koontz was no longer a beginner, that he had been writing for more than two years and that a certain number of stories under his signature had preceded this one. We read them: all were interesting and showed a very personal talent. We will present them later in Fiction, with the pleasure that we always feel when we discover a new author. Let us add that Dean R. Koontz is still very young, being only 23 years old, and such early and promising beginnings suggest that he will be able to go far.”
[English translation via Google Translate]