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 phong
cong san » cong tac
than tap » toan tap, han tap, than cap
phan tap » phan lap, han tap, pha tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc chiet tach - hanh han ((va phung) OR (va nhung)) cong san ((than tap) or (phan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chiet tach - hanh han ((va phung) OR (va nhung)) cong san ((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) OR (va nhung)) cong san ((than tap) or (phan tap))".
• Adding a wildcard symbol may retrieve word variants: hoc chiet tach - hanh han ((va phung) OR (va nhung)) cong san ((than tap) or (phan tap))*.