Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 2, pages 105-192

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 3, pages 203-204

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 3, pages 205-208

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 1, pages 19-23

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 3, pages 193-202

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 1, pages 69-87

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 3, pages 227-230

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 4, pages 289-294

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 4, pages 323-326

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 4, pages 231-269

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 4, pages 297-310

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 4, pages 271-287

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 4, pages 295-296

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 1, pages 29-36

Published in Transactions of the Royal Society of South Africa, in 1917, in volume 6, issue 1, pages 47-68