Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
sach ky » sac ky, sach y, sach ty
van hac » van hoc, van ha, van hai
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
luc va » duc va, tuc va
loc va » hoc va
vai su » va su, van su, lai su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky ((nang xa) or (lang xa)) hoi. hieu van hac ((luc va) OR (loc va)) hanh vai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (lang xa)) hoi. hieu van hac ((luc va) OR (loc va)) hanh vai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (lang xa)) hoi. hieu van hac ((luc va) OR (loc va)) hanh vai su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (lang xa)) hoi. hieu van hac ((luc va) OR (loc va)) hanh vai su triet*.