Published in Philippine Journal of Science, in 1917, in volume 12, pages 163-175

Created: 2017-10-12, modified: 2017-10-12

Published in Philippine J. Sci. Manila D., in 1917, in volume 12, issue 5, pages 267-279

Created: 2012-11-15, modified: 2012-11-15

Published in The Philippine journal of science, in 1917, in volume 12D, pages 249-259

Created: 2012-09-29, modified: 2012-09-29