Perhaps you should try some spelling variations:
nam thuoc » nam thu, nha thuoc, cay thuoc
cua viet » ca viet, hoa viet, cua vat
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
nam thuc » am thuc, nam thu, nam tu
ky sang » ky nang, ky dang, ky tang
vai cua » dai cua, hai cua, lai cua
hieu ve » hieu va, hieu van
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
ma hoi » mai hoi, ma hoa, me hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky sang ((ma hoi) OR (xa hoi)). hieu ve ((nam thuc) or (nam thuoc)) van hanh vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky sang ((ma hoi) OR (xa hoi)). hieu ve ((nam thuc) OR (nam thuoc)) van hanh vai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky sang ((ma hoi) OR (xa hoi)). hieu ve ((nam thuc) or (nam thuoc)) van hanh vai cua viet".
• Adding a wildcard symbol may retrieve word variants: su sac ky sang ((ma hoi) OR (xa hoi)). hieu ve ((nam thuc) or (nam thuoc)) van hanh vai cua viet*.