Perhaps you should try some spelling variations:
thieu bien » thieu nien, tieu bieu, hien bien
lang van » dang van, tang van, hoang van
ve triet » va trien, su triet
lang xa » lang ha, dang xay
sach ky » sac ky, sach y, sach ty
cac duc » cac du, cao duc, cac nuoc
cac dac » cac dan, cac dai, cac bac
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
vi ve » va ve, gi ve, ve ve

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 xa) or (lang van)) hoi. thieu bien ((cac duc) OR (cac dac)) va hanh vi ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((lang xa) OR (lang van)) hoi. thieu bien ((cac duc) OR (cac dac)) va hanh vi ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((lang xa) or (lang van)) hoi. thieu bien ((cac duc) OR (cac dac)) va hanh vi ve triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((lang xa) or (lang van)) hoi. thieu bien ((cac duc) OR (cac dac)) va hanh vi ve triet*.