http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
"Most of the ... papers were prepared during the year 1914 ... Onlytwo of them (nos. XV and XVIII) have heretofore been published in the form here given ... Number XXI was published originaly in substantially its present form in School and society." - Pref.