Perhaps you should try some spelling variations:
"value h2o ratio" » "value 2 ratio", "value 12 ratio", "value 32 ratio", "value h2o reaction", "value h2o ratios", "value h25 ratio", "value h22 ratio"
"value how ratio" » "value how ratios", "value how radio", "value low ratio"
"value co ratio" » "value co ratios", "value c5 ratio", "value c2 ratio"
"value o ratio" » "value 4 ratio", "value 3 ratio", "value 2 ratio", "value o ratios", "value 5 ratio"

Try widening your search to All Fields.

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: (((("value co ratio") OR ("value o ratio"))) OR ((("value h2o ratio") OR ("value how ratio")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"value co ratio\") OR (\"value o ratio\"))) or (((\"value h2o ratio\") or (\"value how ratio\"))))".
• Removing quotes may allow a broader search: (((( value co ratio ) OR ( value o ratio ))) or ((( value h2o ratio ) or ( value how ratio )))).
• Adding a wildcard symbol may retrieve word variants: (((("value co ratio") OR ("value o ratio"))) or ((("value h2o ratio") or ("value how ratio"))))*.