Published in The Philippine journal of science, in 1906, in volume 1, pages 229-236

Created: 2012-09-06, modified: 2012-09-06

Published in Philippine Journal of Science, in 1906, in volume 1, pages 683-695

Created: 2012-05-29, modified: 2012-05-29

Published in The Philippine journal of science, in 1906, in volume 1, issue Supplement 3, pages 169-246

Created: 2016-03-13, modified: 2016-03-13