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