A TOC in Wikipedia is only generated if the article has more than three sections. The one you linked to only has three, and so it is not generated.
If you were to add __TOC__
or __FORCETOC__
to the document a TOC would be generated. __FORCETOC__
causes the TOC to be placed before the first section heading, which would be before "Publications", while __TOC__
will cause the TOC to be inserted wherever it was placed.
For more information you might want to look at WP:TOC, which goes into more depth on how TOCs are generated in Wikipedia and how to control them.