Perhaps you should try some spelling variations:
chiet tach » chieu sach
hoc chiet » hoc thiet, hoc nhiet, hoc hien
hanh hang » thanh hang, hang hang, hanh han
vat dung » van dung, viet dung, mat duong
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap
va dung » van dung, va duong, va ung

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc chiet tach - hanh hang ((va dung) OR (vat dung)) cong tac toan cau~".
• Adding a wildcard symbol may retrieve word variants: hoc chiet tach - hanh hang ((va dung) OR (vat dung)) cong tac toan cau*.