Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh vai » thanh hai, thanh van, thanh tai
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
nam dua » nam da, nam cua, nam mua
dua ban » dia ban, cua ban, qua ban
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach tu nang ((xa hoi) or (ma hoa)). hieu van nam dua ban thanh vai ((cuu tre) OR (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach tu nang ((xa hoi) OR (ma hoa)). hieu van nam dua ban thanh vai ((cuu tre) OR (cua tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach tu nang ((xa hoi) or (ma hoa)). hieu van nam dua ban thanh vai ((cuu tre) OR (cua tre))*".