Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cau tren » cu tren, dau tren, ca tren
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
hieu van » thien van, lieu va, hieu ve
thanh vi » hanh vi, thanh va, thanh ve
cuu tre » cua tre, cau treo
duc ban » duc tan, duc van, dua ban
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
dao duc » giao duc, tao duoc
x hoi » xa hoi, o hoi, x ho

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 thu nang x hoi. ((hieu van) or (hieu va)) dao duc ban thanh vi ((cuu tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu nang x hoi. ((hieu van) OR (hieu va)) dao duc ban thanh vi ((cuu tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: su sach thu nang x hoi. ((hieu van) or (hieu va)) dao duc ban thanh vi ((cuu tre) or (cau tren))*.