Published in Philippine Journal of Science, in 1923, in volume 22, pages 141-142

Published in Philippine Journal of Science, in 1923, in volume 22, pages 143-155

Published in Philippine Journal of Science, in 1923, in volume 22, pages 387-391

Published in Philippine Journal of Science, in 1923, in volume 22, pages 488-513

Published in Philippine Journal of Science, in 1923, in volume 23, pages 67-73