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 dan
tan yang » dan yang, tan ying, tan yong
can post » can past, can postal, can boost
can lost » can lose, can boost, can close
can cost » can costa, chain cost, 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 yang ((can post) OR (((can lost) OR (can cost)))) patients risk among peers ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang tan yang ((can post) or (((can lost) OR (can cost)))) patients risk among peers ;~".
• Adding a wildcard symbol may retrieve word variants: wang tan yang ((can post) or (((can lost) OR (can cost)))) patients risk among peers ;*.