Published in Nautilus, in 1961, in volume 74, pages 102-105

Published in Nautilus, in 1961, in volume 74, pages 131-136

Published in Nautilus, in 1961, in volume 74, pages 136-142

Published in Nautilus, in 1961, in volume 74, pages 149-157

Published in Nautilus, in 1961, in volume 74, pages 166

Published in Nautilus, in 1961, in volume 75, pages 19-20

Published in Nautilus, in 1961, in volume 75, pages 43-49

Published in Nautilus, in 1961, in volume 75, pages 84