Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
danh hai » dang hai, lanh hai, manh hai
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
quoc ban » quoc bao, quoc lan, quoc quan
van lam » van nam
sach ky » sac ky, sach y, sach ty
duc van » duc va, duc tan, duc manh
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, 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 ky tang xa hoi. hieu van lam ((quoc ban) or (duc van)) danh hai ((cua tre) OR (cua triet))~.
• 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 (cua triet)).
• 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 (cua triet))".
• 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 (cua triet))*.