Perhaps you should try some spelling variations:
"gramian symmetry" » "galilean symmetry", "family symmetry", "graph symmetry"
"brain symmetry" » "brain dissymmetry", "britain asymmetry", "broken symmetry"
"brain asymmetry" » "brain asymmetric"

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("brain asymmetry") OR ((("brain symmetry") OR ("gramian symmetry")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"brain asymmetry\") or (((\"brain symmetry\") OR (\"gramian symmetry\"))))".
• Removing quotes may allow a broader search: (( brain asymmetry ) or ((( brain symmetry ) OR ( gramian symmetry )))).
• Adding a wildcard symbol may retrieve word variants: (("brain asymmetry") or ((("brain symmetry") OR ("gramian symmetry"))))*.