Perhaps you should try some spelling variations:
nam thuoc » nam thu, nha thuoc, cay thuoc
day manh » van manh, duc manh, ha manh
nam thuc » am thuc, nam thu, nam tu
sach ky » sac ky, sach y, sach ty
manh ba » manh cua, danh bat, manh hai
tu sach » thu sach, su sach, te sach
ca viet » va viet, co viet, hoa viet
hieu ve » hieu va, hieu van
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi
ba ca » bai ca, ba cau, ba na

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 ky nang ((x hoi) or (o hoi)). hieu ve ((nam thuoc) OR (nam thuc)) day manh ba ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (o hoi)). hieu ve ((nam thuoc) OR (nam thuc)) day manh ba ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) or (o hoi)). hieu ve ((nam thuoc) OR (nam thuc)) day manh ba ca viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (o hoi)). hieu ve ((nam thuoc) OR (nam thuc)) day manh ba ca viet*.