Perhaps you should try some spelling variations:
hieu vien » hieu hien, thieu nien, hieu tieng
sach luoc » sach duoc, sach nuoc, sach luan
hieu viec » nhieu viec, hieu ve, sieu viet
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
tai hoi » tai khoi, tai hai, tai hoe
dai hoi » dai hoc, dai hai, dai moi
luoc va » nuoc va, duoc va, loc va
tu bai » tu ban, tu bat, te bai
vi cua » vai cua, di cua
bai ky » ban ky, sai ky, bac ky
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: tu bai ky nang ((tai hoi) or (dai hoi)). ((hieu vien) OR (hieu viec)) sach luoc va thanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu bai ky nang ((tai hoi) OR (dai hoi)). ((hieu vien) OR (hieu viec)) sach luoc va thanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu bai ky nang ((tai hoi) or (dai hoi)). ((hieu vien) OR (hieu viec)) sach luoc va thanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: tu bai ky nang ((tai hoi) or (dai hoi)). ((hieu vien) OR (hieu viec)) sach luoc va thanh vi cua te*.