Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
danh hai » dang hai, lanh hai, manh hai
quoc ban » quoc bao, quoc lan, quoc quan
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
duc van » duc va, duc tan, duc manh
sach ky » sac ky, sach y, sach ty
van lam » van nam
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang

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 ky tang xa hoi. hieu van lam ((quoc ban) or (duc van)) danh hai ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky tang xa hoi. hieu van lam ((quoc ban) OR (duc van)) danh hai ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky tang xa hoi. hieu van lam ((quoc ban) or (duc van)) danh hai ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: thu sach ky tang xa hoi. hieu van lam ((quoc ban) or (duc van)) danh hai ((cua tre) OR (cuu tre))*.