Perhaps you should try some spelling variations:
thieu bien » thieu nien, hien bien, hieu hien
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh
via cua » gia cua, gian cua, giau cua
ca cua » co cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang xa hoi. ((thieu bien) OR (tieu bieu)) cac duc va hanh ((via cua) or (ca cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang xa hoi. ((thieu bien) OR (tieu bieu)) cac duc va hanh ((via cua) OR (ca cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang xa hoi. ((thieu bien) OR (tieu bieu)) cac duc va hanh ((via cua) or (ca cua)) triet".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang xa hoi. ((thieu bien) OR (tieu bieu)) cac duc va hanh ((via cua) or (ca cua)) triet*.