Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
lam duoc » nam duoc, luat duoc, lam thuoc
van lam » van nam
va tinh » may tinh
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
dai hoi » dai hoc, dai hai, dai moi
mai hoi » mai khoi, lai hoi, mai doi
ca cua » co cua
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: so sach ky nang ((mai hoi) OR (dai hoi)). hieu van lam duoc ((va tinh) or (gia thanh)) ca cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang ((mai hoi) OR (dai hoi)). hieu van lam duoc ((va tinh) OR (gia thanh)) ca cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang ((mai hoi) OR (dai hoi)). hieu van lam duoc ((va tinh) or (gia thanh)) ca cua te".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang ((mai hoi) OR (dai hoi)). hieu van lam duoc ((va tinh) or (gia thanh)) ca cua te*.