http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
by Maurice Leven, Harold G. Moulton and Clark Warburton.
Volume 2 of "The distribution of wealth and income in relation to economic progress." cf. Director's pref.
Publication (Brookings Institution. Institute of Economics) ; no.56