Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
nam thuc » nam thuoc, am thuc, nam thu
thuc day » thuc dan, thuc vat
day hanh » day nhanh, day thanh, dao hanh
sach ky » sach y, sach ty, sach kem
cuu tre » cua tre, cau tren, cau treo
sac ky » cac ky, sai ky
vi cuu » vi luu, vinh cuu
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: su ((sach ky) OR (sac ky)) nang x hoi. ((hieu van) OR (thien van)) nam thuc day hanh vi cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sac ky)) nang x hoi. ((hieu van) or (thien van)) nam thuc day hanh vi cuu tre~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sac ky)) nang x hoi. ((hieu van) or (thien van)) nam thuc day hanh vi cuu tre*.