Perhaps you should try some spelling variations:
hieu thien » chieu chien, dieu khien, bieu hien
hieu hien » bieu hien, dieu hien, chieu chien
van hanh » van thanh, ban hanh, van anh
vai cua » dai cua, hai cua, lai cua
va hanh » va thanh, va danh, ban hanh
vu sach » vu bach, su sach, vu khach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
cac co » cac cong
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ty nang xa hoi. ((hieu thien) OR (hieu hien)) cac co ((va hanh) or (van hanh)) vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty nang xa hoi. ((hieu thien) OR (hieu hien)) cac co ((va hanh) OR (van hanh)) vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty nang xa hoi. ((hieu thien) OR (hieu hien)) cac co ((va hanh) or (van hanh)) vai cua te".
• Adding a wildcard symbol may retrieve word variants: vu sach ty nang xa hoi. ((hieu thien) OR (hieu hien)) cac co ((va hanh) or (van hanh)) vai cua te*.