Perhaps you should try some spelling variations:
"1997 world trotting championships" » "1997 world fighting championship", "1997 world winning championships", "1997 world treating championships", "1997 world trusting championships", "1997 world protecting championships", "1994 world trotting championships", "1995 world trotting championships", "1999 world trotting championships"
"1997 world testing championships" » "1997 world winning championships", "1997 world testing relationships", "1997 world fighting championship", "1997 world treating championships", "1997 world setting championships", "1997 world getting championships", "1994 world testing championships", "1995 world testing championships", "1999 world testing championships"
"1993 world testing championships" » "1993 world winning championships", "1993 world testing relationships", "1993 world fighting championship", "1993 world treating championships", "1993 world setting championships", "1993 world getting championships"
"1992 world testing championships" » "1992 world winning championships", "1992 world testing relationships", "1992 world fighting championship", "1992 world treating championships", "1992 world setting championships", "1992 world getting championships"

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: (("1997 world trotting championships") OR ((((("1997 world testing championships") OR ("1993 world testing championships"))) OR ("1992 world testing championships")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"1997 world trotting championships\") or (((((\"1997 world testing championships\") OR (\"1993 world testing championships\"))) or (\"1992 world testing championships\"))))".
• Removing quotes may allow a broader search: (( 1997 world trotting championships ) or ((((( 1997 world testing championships ) OR ( 1993 world testing championships ))) or ( 1992 world testing championships )))).
• Adding a wildcard symbol may retrieve word variants: (("1997 world trotting championships") or ((((("1997 world testing championships") OR ("1993 world testing championships"))) or ("1992 world testing championships"))))*.