Perhaps you should try some spelling variations:
nang dong » nang song, lang dong, nang luong
ve triet » va trien, su triet
nang noi » nang doc
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
van hoc » van hoa
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
cac tac » cac toc, cac bac, cac dac
tac xa » tuc xa, tac da

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 lang) OR (ky dang)) van hoc. hieu va cac tac xa ((nang dong) or (nang noi)) ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky dang)) van hoc. hieu va cac tac xa ((nang dong) OR (nang noi)) ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky lang) OR (ky dang)) van hoc. hieu va cac tac xa ((nang dong) or (nang noi)) ve triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) OR (ky dang)) van hoc. hieu va cac tac xa ((nang dong) or (nang noi)) ve triet*.