Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
va triet » va thiet, va trien, ve triet
hieu van » hieu va, thien van, lieu va
truc va » thuc va, thuc vat, trung va
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
van cau » van dau, van hau, van chat
nang xa » nang x, lang xa, nang ma
tuc va » thuc va, tuc xa, duc va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu van cau ((tuc va) OR (truc va)) hanh kem ((cua triet) OR (va triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu van cau ((tuc va) OR (truc va)) hanh kem ((cua triet) or (va triet))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu van cau ((tuc va) OR (truc va)) hanh kem ((cua triet) or (va triet))*.