Perhaps you should try some spelling variations:
david young » david loundy
study gene » study gender, study genetic, study agency
mark david » mare davide, parker david
gene mark » gene bank, gene part, nene marc
young ghi » young choi, hong ghi, young get
yao yang » yang yang
yan yang » yang yang, dan yang, tan yang

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

• Performing a fuzzy search may retrieve terms with similar spellings: (wing or wan) ((yan yang) OR (yao yang)) study gene mark david young ghi ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (wing OR wan) ((yan yang) OR (yao yang)) study gene mark david young ghi ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(wing or wan) ((yan yang) OR (yao yang)) study gene mark david young ghi ;".
• Adding a wildcard symbol may retrieve word variants: (wing or wan) ((yan yang) OR (yao yang)) study gene mark david young ghi ;*.