Published in Philippine Journal of Science, in 1921, in volume 17, pages 343-351

Published in Philippine Journal of Science, in 1921, in volume 18, pages 259-288

Published in Philippine Journal of Science, in 1921, in volume 18, pages 557-593

Published in Philippine Journal of Science, in 1921, in volume 18, pages 637-677

Published in Philippine Journal of Science, in 1921, in volume 18, pages 679-687

Published in Philippine Journal of Science, in 1921, in volume 18, issue 3, pages 243-257

Published in Philippine Journal of Science, in 1921, in volume 19, pages 23-63