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Hi~~~I'm desperately searching for a book I received as a birthday gift when I was 11 or 12 (which would have been in 1981-82). It was a collection of unicorn stories and although I was young, the person who gave it to me must not have read it first as it was not a children's book! Most if not all of the stories were science-fiction. At least one story I remember had mature content involving intimate relations with a Centaur, and another story I remember had to do with future vehicles that would drive themselves after having one's destination typed into the controls (or maybe spoken?) Yet still another one I recall had to do with traveling in a time machine---fueled by synthetic gemstones, I believe---back to a time when the air was so clean that the time travelers could not breathe the air for long. I CANNOT for the life of me remember the title of this book, nor any of the short stories' titles within! If any of this info sounds familiar, could you pretty please let me know??? I would love to own or at least read this book again. Every story had something to do with unicorns, but happy endings were not necessarily the norm. Thanks for any help!