Perhaps you should try some spelling variations:
nam thuoc » nam thu, nha thuoc, cay thuoc
doan manh » doan minh, hoang manh, tran manh
nam thuc » am thuc, nam thu, nam tu
dan manh » dang manh, van manh, day manh
cua viet » ca viet, hoa viet, cua vat
hieu ve » hieu va, hieu van
vai cua » dai cua, hai cua, lai cua
tu sach » thu sach, su sach, te sach
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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 y nang o hoi. hieu ve ((nam thuc) or (nam thuoc)) ((dan manh) OR (doan manh)) vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang o hoi. hieu ve ((nam thuc) OR (nam thuoc)) ((dan manh) OR (doan manh)) vai cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang o hoi. hieu ve ((nam thuc) or (nam thuoc)) ((dan manh) OR (doan manh)) vai cua viet*".