Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
ve triet » va trien
hieu van » hieu va, thien van, lieu va
su triet » su viet, su tien
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
van cac » van hac, van cau, van bac
su sai » su tai, su hai, su dai
sai ky » sac ky
luc va » tuc va, loc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sai ky tang xa hoi. hieu van cac ((luc va) or (duc va)) thanh doi ((su triet) OR (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky tang xa hoi. hieu van cac ((luc va) OR (duc va)) thanh doi ((su triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sai ky tang xa hoi. hieu van cac ((luc va) or (duc va)) thanh doi ((su triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: su sai ky tang xa hoi. hieu van cac ((luc va) or (duc va)) thanh doi ((su triet) OR (ve triet))*.