Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
dinh lam » dinh van, tinh lao
hieu van » thien van, lieu va, hieu ve
va dinh » van dinh, va kinh, va tinh
thuc va » thuc vat, thuc dan, thuc day
sach ky » sac ky, sach y, sach kem
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
lam su » lai su, lam so, lam vu
x hoi » xa hoi, o hoi, x ho

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) OR (sach ty)) nang x hoi. ((hieu va) OR (hieu van)) am thuc va dinh lam su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang x hoi. ((hieu va) or (hieu van)) am thuc va dinh lam su triet~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang x hoi. ((hieu va) or (hieu van)) am thuc va dinh lam su triet*.