Perhaps you should try some spelling variations:
patients risk » patient risk, patients links, patients si
among peers » among ers, among users, among letters
wang tan » wang yan, wang ban, wang tao
wang dan » wang yan, wang ban, wang yidan
can post » can cost, can past, can postal
can lost » can cost, can lose, can boost

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: ((wang tan) OR (wang dan)) yang ((can post) OR (can lost)) patients risk among peers ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang tan) OR (wang dan)) yang ((can post) or (can lost)) patients risk among peers ;~".
• Adding a wildcard symbol may retrieve word variants: ((wang tan) OR (wang dan)) yang ((can post) or (can lost)) patients risk among peers ;*.