http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Nesting weights, Einsatzgewichte and piles à godets
a catalog of nested cup weights in the Edward Clark Streeter Collection of weights and measures
Transactions of the Connecticut Academy of Arts and Sciences ; v. 50, p. 1-117