Perhaps you should try some spelling variations:
sach tien » sach tren, sach thieu
tien nang » thien nang, trien nang, tin nang
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
su sach » so sach, vu sach
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
van lam » van nam
nang xa » nang x, lang xa, nang ma
xuc va » tuc va, luc va, xac 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 lam ((xuc va) OR (duc 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 lam ((xuc va) OR (duc 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 lam ((xuc va) OR (duc va)) thanh vi ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach tien nang xa hoi. hieu van lam ((xuc va) OR (duc va)) thanh vi ((cua tre) or (cuu tre))*.