Perhaps you should try some spelling variations:
sach thien » sach thieu, sach tien, cach thien
thien lang » thien bang, thien dang, thien nang
hieu van » hieu va, thien van, lieu va
dua tren » dung tren
su sach » so sach, vu sach
cuu tre » cau tren, cau treo
dinh vi » dinh ve, dinh viet, dinh tri
va dinh » van dinh, va kinh, va tinh
nam xuc » cam xuc, nam xua, nam thuc
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cua triet, cua thep
xuc va » duc va, tuc va, luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach thien lang xa hoi. hieu van nam xuc va dinh vi ((dua tren) or (((cuu tre) OR (cua tre))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thien lang xa hoi. hieu van nam xuc va dinh vi ((dua tren) OR (((cuu tre) OR (cua tre)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thien lang xa hoi. hieu van nam xuc va dinh vi ((dua tren) or (((cuu tre) OR (cua tre))))".
• Adding a wildcard symbol may retrieve word variants: su sach thien lang xa hoi. hieu van nam xuc va dinh vi ((dua tren) or (((cuu tre) OR (cua tre))))*.