Perhaps you should try some spelling variations:
thu nang » thi nang, thu hang, thu bang
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
sach thu » sach thue, sach thieu, sach tham
so sach » so sanh, bo sach, co sach
vai cua » dai cua, hai cua, lai cua
huu van » cuu van, huu han, luu van
ve pham » vi pham, v pham, ve phat
ve phan » va phan, ke phan, ve phat
cao hoi » cau hoi, cao hoc, tao hoi
co hoi » co hoc, co loi
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 thu nang ((cao hoi) or (co hoi)). hieu ((ve pham) OR (ve phan)) huu van hanh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thu nang ((cao hoi) OR (co hoi)). hieu ((ve pham) OR (ve phan)) huu van hanh vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach thu nang ((cao hoi) or (co hoi)). hieu ((ve pham) OR (ve phan)) huu van hanh vai cua te".
• Adding a wildcard symbol may retrieve word variants: so sach thu nang ((cao hoi) or (co hoi)). hieu ((ve pham) OR (ve phan)) huu van hanh vai cua te*.