Perhaps you should try some spelling variations:
cross patient » class patient, proms patient, access patient
des patients » des patents, les patients, des patienten
wang yang » wang yan, wang liang, wang yanling
risk tong » risk among, risk along
tong shui » tong hui, cong shu, gong hui
yang jun » yang jui, pang jun, yang jin

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 yang ((hang ups) OR (yang jun)) ((des patients) OR (cross patient)) risk tong shui ;~.
• Adding a wildcard symbol may retrieve word variants: wang yang ((hang ups) or (yang jun)) ((des patients) or (cross patient)) risk tong shui ;*.