Most publishers have TOC services for new issues of their journals.
JournalTOCs aggregates TOCs from publishers and maintains a searchable database of their TOC postings.
A database that is accessible via a free API I should add.
The API should be a useful way to add journal articles to a topic map, particularly when you want to add selected articles and not entire issues.
I am looking forward to using and exploring JournalTOCs.
Suggest you do the same.