Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
va trien » va truyen, va thiet, va tuyen
hieu van » hieu va, thien van, lieu va
ve triet » su triet
va thanh » gia thanh, ban thanh, va tinh
cac luc » cau luc, coc luc, cac nuoc
van cac » van hac, van cau, van bac
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
luc va » duc va, tuc va, loc va
su dai » sau dai, si dai, su tai
su sai » su tai, su hai, su mai

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