Perhaps you should try some spelling variations:
ratings risk » patients risk
cost ratings » cost savings, costs savings, bond ratings
cheng zhang » cheng han, zhen zhang, chen zheng
risk along » risk among, ask along
along shu » along nhue, cong shu, along who
ming yu » ming lu, ming yi, mang yul
ping yu » ping ku, ping yi

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: cheng zhang ((ming yu) OR (ping yu)) cost ratings risk along shu ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "cheng zhang ((ming yu) OR (ping yu)) cost ratings risk along shu ;*".