Perhaps you should try some spelling variations:
"liver cancer relevance" » "liver matter relevance", "liver cancer resistance", "liver cancer references"
"silver change relevant" » "silver changes relevant", "silver change relevance", "silver change recent", "silver charge relevant", "silver exchanged relevant", "silver chapter relevant"

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: "((\"silver change relevant\") OR (\"liver cancer relevance\"))".
• Removing quotes may allow a broader search: (( silver change relevant ) OR ( liver cancer relevance )).
• Adding a wildcard symbol may retrieve word variants: (("silver change relevant") OR ("liver cancer relevance"))*.