The LawBod's collection of public international law journals have shelf marks beginning Internat 300.
For issues from & including 2000 are on Floor 3. Earlier issues (from & including 1999) are on Ground Floor.
The arrangement is then alphabetical, by the first word of the journal's title.
Yearbooks can be an exception - eg. yearbooks of the UN & its organs may well be in Official Papers.
Working papers, pre-prints, OA and Institutional Repositories
Institutional repositories from the English speaking world can often be tracked down by a www search combining Scholarly commons or Scholarly communications with the name of the university.