Published in Journal of the Washington Academy of Sciences, in 1917, in volume 7, pages 127-131

Published in Journal of The Washington Academy of Sciences, in 1917, in volume 7, pages 388-392

Published in Journal of The Washington Academy of Sciences, in 1917, in volume 7, pages 504-512

Published in Washington Dc J Acad Sci, in 1917, in volume 7, pages 537-538