Perhaps you should try some spelling variations:
chiet tach » chieu sach
hoc chiet » hoc thiet, hoc nhiet, hoc hien
hanh han » hanh nhan, hanh phan, hanh san
va phung » va phuong, van phung, va nhung
cong tac » cong ty
than tap » toan tap, han tap, than cap
phan tap » phan lap, han tap, pha tap
han va » hang va, hanh va, nhan va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chiet tach - hanh han va phung ((cong san) OR (cong tac)) ((than tap) OR (phan tap))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc chiet tach - hanh han va phung ((cong san) OR (cong tac)) ((than tap) or (phan tap))~".
• Adding a wildcard symbol may retrieve word variants: hoc chiet tach - hanh han va phung ((cong san) OR (cong tac)) ((than tap) or (phan tap))*.