Perhaps you should try some spelling variations:
nam thuoc » nam thu, nha thuoc, cay thuoc
cua viet » ca viet, hoa viet, cua vat
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
nam thuc » am thuc, nam thu, nam tu
hieu ve » hieu va, hieu van
dang ma » dang mau, dang mam, dang mat
ky dang » ky nang, ky danh
su sach » so sach, vu sach
ma hoi » mai hoi, xa hoi, ma hoa
su sac » su cac, su xac

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) or (su sach)) ky dang ma hoi. hieu ve ((nam thuc) or (nam thuoc)) van hanh dai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (su sach)) ky dang ma hoi. hieu ve ((nam thuc) OR (nam thuoc)) van hanh dai cua viet.
• Adding a wildcard symbol may retrieve word variants: ((su sac) or (su sach)) ky dang ma hoi. hieu ve ((nam thuc) or (nam thuoc)) van hanh dai cua viet*.