http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Workbook 1 -- Workbook 2 -- Workbook 3 --Workbook and glossary 2A -- Workbook and glossary 2B.
From workbook 2 onwards, by Peter Boaks, Christopher Boyce and Ebba-Maia Dudde.