Perhaps you should try some spelling variations:
"Hilbert's teeth problem" » "Hilbert's teets problem"
"Hilbert's tent problem" » "Hilbert's tenti problem", "Hilbert's text problem", "Hilbert's test problem"
"Hilbert's tenth problems" » "Hilbert's tentih problems", "Hilbert's texth problems", "Hilbert's testh problems", "Hilbert's tenti problems", "Hilbert's benth problems", "Hilbert's tench problems", "Hilbert's tenth problemas", "Hilbert's tenth problema"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("Hilbert's teeth problem") OR ("Hilbert's tent problem"))) OR ("Hilbert's tenth problems"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"Hilbert's teeth problem\") OR (\"Hilbert's tent problem\"))) OR (\"Hilbert's tenth problems\"))".
• Removing quotes may allow a broader search: (((( Hilbert's teeth problem ) OR ( Hilbert's tent problem ))) OR ( Hilbert's tenth problems )).
• Adding a wildcard symbol may retrieve word variants: (((("Hilbert's teeth problem") OR ("Hilbert's tent problem"))) OR ("Hilbert's tenth problems"))*.