Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 1-47

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 85-149

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 150-170

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 171-175

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 176-183

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 184-193

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 194-223

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 224-236

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 237-244

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 245-260

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 261-267

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 313-324

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 325-370

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 371-404

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 405-511

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 512-516

Published in Proceedings of The American Philosophical Society, in 1920, in volume 59, issue 220, pages 517-531