Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nang doc » nang luc
va triet » va thiet, va trien, ve triet
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
ve cac » va cac, vien cac
tu xa » tu va, te xa, tu ma

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 ve cac ((tu xa) or (tu xay)) ((nang doc) or (nang noi)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky tang xa hoi. hieu ve cac ((tu xa) OR (tu xay)) ((nang doc) OR (nang noi)) va triet.
• Adding a wildcard symbol may retrieve word variants: thu sach ky tang xa hoi. hieu ve cac ((tu xa) or (tu xay)) ((nang doc) or (nang noi)) va triet*.