Perhaps you should try some spelling variations:
among parents » among patients, among ports
patients 1.8 » patients 10.1, patients 10.5, patients 10.6
de patients » des patients, do patients, de pacientes
yang yang » wang yang, wang yan
1.8 among » 1.5 among, 19 among, 1 among
yan yang » dan yang, tan yang, yan wang
van de » van der, van den
wang » wing, wan

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