Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
ban hanh » ban hang
va triet » va trien, ve triet, cua triet
sinh ky » sinh ly, sinh y, kinh ky
cao hoi » cau hoi, co hoi, cao hoc
nam tuc » nam thuc, nam truc, nam tu
va nam » van nam, ha nam, va nay
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sinh ky nang cao hoi. lieu va nam tuc ((va thanh) or (ban hanh)) di ((va triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sinh ky nang cao hoi. lieu va nam tuc ((va thanh) OR (ban hanh)) di ((va triet) OR (va thiet)).
• Adding a wildcard symbol may retrieve word variants: hoc sinh ky nang cao hoi. lieu va nam tuc ((va thanh) or (ban hanh)) di ((va triet) or (va thiet))*.