Perhaps you should try some spelling variations:
nguoi tay » nguoi thai
tri nguoi » tri nguon, tren nguoi, toc nguoi
khoa hoc » hoa hoc
khong he » khong khi, hong ha, khong _
tu sach » thu sach, su sach, tu cach
te sach » toc sach
khoa he » hoa he, khoa thu, khoa hoi
thong » trong

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (te sach)) tri nguoi tay ((((khoa he) or (khoa hoc))) or (khong he)) thong~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) tri nguoi tay ((((khoa he) OR (khoa hoc))) OR (khong he)) thong.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) tri nguoi tay ((((khoa he) or (khoa hoc))) or (khong he)) thong*.