Perhaps you should try some spelling variations:
ve triet » va trien, su triet
nang doc » nang luc
nang doi » nang noi, hang doi, nang dong
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
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: tu sach ky tang xa hoi. hieu ve cac ((tu xa) or (tu xay)) ((nang doi) or (nang doc)) ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang xa hoi. hieu ve cac ((tu xa) OR (tu xay)) ((nang doi) OR (nang doc)) ve triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang xa hoi. hieu ve cac ((tu xa) or (tu xay)) ((nang doi) or (nang doc)) ve triet*.