Published in Journal of The Washington Academy of Sciences, in 1919, in volume 9, pages 35-38

Published in Journal of The Washington Academy of Sciences, in 1919, in volume 9, pages 136-138

Published in Washington Dc J Acad Sci, in 1919, in volume 9, pages 167-168

Published in Journal of the Washington Academy of Science, in 1919, in volume 9, pages 241-252

Published in Journal of The Washington Academy of Sciences, in 1919, in volume 9, issue 6, pages 157-167

Published in Journal of The Washington Academy of Sciences, in 1919, in volume 9, issue 13, pages 364-373

Published in Journal of The Washington Academy of Sciences, in 1919, in volume 9, issue 15, pages 431-438

Published in Journal of The Washington Academy of Sciences, in 1919, in volume 9, issue 16, pages 457-462

Published in Journal of The Washington Academy of Sciences, in 1919, in volume 9, issue 18, pages 546-551