Perhaps you should try some spelling variations:
patients 10.1 » patients 10.12, patients 10.5, patients 10.6
among letters » among lecturers, among learners, among masters
among farmers » salmon farmers
des patients » des patents, les patients, des patienten
zhang zhang » zhen zhang, cheng zhang, zhang han
zhang fang » zhang fan, zhang yan, zhang ming
meng yuan » meng hsuan, fang yuan, feng juan

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: meng yuan ((zhang zhang) OR (zhang fang)) des patients 10.1 ((among letters) OR (among farmers)) ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "meng yuan ((zhang zhang) OR (zhang fang)) des patients 10.1 ((among letters) or (among farmers)) ;~".
• Adding a wildcard symbol may retrieve word variants: meng yuan ((zhang zhang) OR (zhang fang)) des patients 10.1 ((among letters) or (among farmers)) ;*.