Published in Contributions in Science, in 1960, in volume 35, pages 1-7
Published in Contributions in Science, in 1960, in volume 36, pages 1-4
Published in Contributions In Science Los Angeles, in 1960, in volume 37, pages 1-8
Published in Contributions in Science Los Angeles, in 1960, in volume 38, pages 1-11
Published in Contributions in Science, in 1960, in volume 39, pages 1-7