Perhaps you should try some spelling variations:
patients 1.8 » patients 10.1, patients 10.5, patients 10.6
among donors » among doctors, among actors
1.8 among » 1.5 among, 19 among, 1 among
yan yang » yang yang, yao yang, tan yang
dan yang » daun yang, tan yang, wang yang
fan de » aan de, jan de, can de
van de » van der, van den

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: wai ((yan yang) OR (dan yang)) ((fan de) OR (van de)) patients 1.8 among donors ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wai ((yan yang) or (dan yang)) ((fan de) OR (van de)) patients 1.8 among donors ;~".
• Adding a wildcard symbol may retrieve word variants: wai ((yan yang) or (dan yang)) ((fan de) OR (van de)) patients 1.8 among donors ;*.