Perhaps you should try some spelling variations:
"all-ireland under-21 world champions" » "all-ireland under-21 world championship", "all-ireland under-21 bowl champions", "all-ireland under-21 norm champions", "all-ireland under-21 world championships", "all-ireland defender-21 world champions", "all-ireland under-21 worlds champions", "all-ireland under-1 world champions", "all-ireland under-2 world champions"
"all-ireland under-21 world champion" » "all-ireland under-21 world championship", "all-ireland defender-21 world champion", "all-ireland under-21 worlds champion", "all-ireland under-1 world champion", "all-ireland under-2 world champion"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"all-ireland under-21 world champions\") OR (\"all-ireland under-21 world champion\"))".
• Removing quotes may allow a broader search: (( all-ireland under-21 world champions ) OR ( all-ireland under-21 world champion )).
• Adding a wildcard symbol may retrieve word variants: (("all-ireland under-21 world champions") OR ("all-ireland under-21 world champion"))*.