http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
"First published, September, 1928 ... sixth impression, February, 1931."
"While the 'To-day and to-morrow' series has been the medium of publication of many brilliant flights of imagination, the present book is limited to scientific facts and such inferences as I think may properly be drawn from them."--Foreword.