Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
cua triet » cua viet, su triet, va triet
thanh di » thanh doi, thanh de, thanh do
nam thuc » nam thuoc, am thuc, nam thu
thuc van » thuc vat, thuc dan, thuc va
su viet » so viet
hoi hoi » hoi hoc, hoc hoi, hoi doi
hieu ve » hieu va, hieu van
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
ho hoi » hoc hoi, hoa hoi, co hoi
ve nam » he nam, va nam, le nam

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 nang ((ho hoi) OR (hoi hoi)). hieu ve nam thuc van thanh di ((cua triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang ((ho hoi) OR (hoi hoi)). hieu ve nam thuc van thanh di ((cua triet) OR (su viet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang ((ho hoi) OR (hoi hoi)). hieu ve nam thuc van thanh di ((cua triet) or (su viet))*".