Perhaps you should try some spelling variations:
"Hilbert's tent problem" » "Hilbert's text problem", "Hilbert's kent problem", "Hilbert's ten problem"
"Hilbert's tenti problem" » "Hilbert's texti problem", "Hilbert's kenti problem", "Hilbert's teni problem"
"Hilbert's test problem" » "Hilbert's text problem", "Hilbert's west problem", "Hilbert's best problem"

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 tent problem") OR ("Hilbert's tenti problem"))) OR ("Hilbert's test problem"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"Hilbert's tent problem\") OR (\"Hilbert's tenti problem\"))) OR (\"Hilbert's test problem\"))".
• Removing quotes may allow a broader search: (((( Hilbert's tent problem ) OR ( Hilbert's tenti problem ))) OR ( Hilbert's test problem )).
• Adding a wildcard symbol may retrieve word variants: (((("Hilbert's tent problem") OR ("Hilbert's tenti problem"))) OR ("Hilbert's test problem"))*.