Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, tu cach
duc ban » duc tan, duc van, dua ban
lam duc » lam duoc, pham duc, nam duoc
van lam » van nam
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
te sach » toc sach
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (te sach)) ky tang xa hoi. hieu van lam duc ban hanh vi ((cua viet) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky tang xa hoi. hieu van lam duc ban hanh vi ((cua viet) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) ky tang xa hoi. hieu van lam duc ban hanh vi ((cua viet) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) ky tang xa hoi. hieu van lam duc ban hanh vi ((cua viet) or (cuu tre))*.