While searching at the USGS Publications Warehouse [1], I noticed one of the available tabs was MIA [2].
Clicking on this tab brought me to the MIA Publication page, where USGS asked the public's help in tracking down missing publications. Here's their explanation:
Listed below are all the USGS series that are currently or will soon be loaded into the Publication Warehouse. Each series may have missing report numbers or unverifiable citations.
Missing report numbers are gaps in the numbering sequence of a series. We do not know if the report was ever released or if there is a reason why the report number was skipped. These reports may have been cancelled, recalled, or destroyed. Report numbers may have been issued in blocks and some may never have been used.
Unverified citations Unverified citations are citations for any publication where there was some information about the publication available but that information could not be confirmed, the publication itself has not been found, and we are not sure if the publication was actually released. Many of the unverified reports were found referenced by other publications as "in press".
Please visit the site for a list of the missing and help out if you can. You'll be responsible for putting more government information on the web.