Perhaps you should try some spelling variations:
tien nang » thien nang, trien nang, tin nang
thien van » thi van
sach tien » sach tren, sach thieu
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, lieu va, hieu ve
thanh vi » hanh vi, thanh va, thanh ve
su sach » so sach, vu sach
cua tre » cua te, cua triet, dua tren
nam xuc » cam xuc, nam xua, nam thuc
nang xa » nang x, lang xa, nang ma
cuu tre » cau tren, cau treo
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 tien nang xa hoi. ((hieu van) OR (thien van)) nam xuc va thanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tien nang xa hoi. ((hieu van) OR (thien van)) nam xuc va thanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tien nang xa hoi. ((hieu van) OR (thien van)) nam xuc va thanh vi ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach tien nang xa hoi. ((hieu van) OR (thien van)) nam xuc va thanh vi ((cua tre) or (cuu tre))*.