Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
su triet » su viet, su tien, ve triet
dinh dat » dinh ket, dinh van, dinh lam
va dinh » van dinh, va kinh, va tinh
thuc va » thuc vat, thuc dan, thuc day
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
dat su » sat su
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 qua) OR (hieu quan)) am thuc va dinh dat 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 qua) or (hieu quan)) am thuc va dinh dat su triet~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang x hoi. ((hieu qua) or (hieu quan)) am thuc va dinh dat su triet*.