http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Weekly (except for first week in Jan.), 2001-2009
Beginning in 2011, regional sections are included in the pages of ENR six times per year in California, the Midwest, Mountain States, the Southeast, the Southwest, and Texas/Louisiana.
Numbering jumps from v. 275, no. 20 (Feb. 1/8, 2016) to v. 276, no. 4 (Feb. 15, 2016) [i.e. Vol. 276, no. 1-3 skipped in numbering].
In 2006 absorbed: Top 500 design firms sourcebook.