Perhaps you should try some spelling variations:
chieu chien » thien chien
hieu hien » bieu hien, dieu hien, dieu khien
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cac lop » cac hop, cac loai
va hanh » van hanh, va thanh, va danh
vai cua » hai cua, lai cua, bai cua
lop va » lap va, hop va, nop va

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 nang xa hoi. ((hieu hien) OR (chieu chien)) cac lop va hanh ((vai cua) or (dai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. ((hieu hien) OR (chieu chien)) cac lop va hanh ((vai cua) OR (dai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. ((hieu hien) OR (chieu chien)) cac lop va hanh ((vai cua) or (dai cua)) te".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. ((hieu hien) OR (chieu chien)) cac lop va hanh ((vai cua) or (dai cua)) te*.