Perhaps you should try some spelling variations:
sach thien » sach thieu, sach tien, cach thien
thien bang » khien bang, thien ban, thien dang
dung tren » dung trong, dung trung
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
dinh ve » dinh ket, dinh van
va dinh » van dinh, va kinh, va tinh
cuu tre » cua tre, cau tren, cau treo
bang xa » lang xa, bang va, mang xa
dam tu » nam tu, tam tu, dam thuc
cam tu » cam thu, nam tu, tam tu

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 thien bang xa hoi. hieu van ((cam tu) OR (dam tu)) va dinh ve ((dung tren) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thien bang xa hoi. hieu van ((cam tu) OR (dam tu)) va dinh ve ((dung tren) or (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: su sach thien bang xa hoi. hieu van ((cam tu) OR (dam tu)) va dinh ve ((dung tren) or (cuu tre))*.