Perhaps you should try some spelling variations:
doi chieu » doc hieu, ho chieu, mot chieu
hanh tang » hanh trang, anh tang, hanh tung
hanh mang » nhanh mang, hanh trang, nhanh lang
dung cong » dung trong
cua dung » cua dang, cua dong, qua dung
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cao » toan ban, toan tap
doi chi » doi khi

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: ((doi chieu) OR (doi chi)) sach - ((hanh tang) OR (hanh mang)) cua dung cong tac toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) OR (doi chi)) sach - ((hanh tang) or (hanh mang)) cua dung cong tac toan cao~".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) OR (doi chi)) sach - ((hanh tang) or (hanh mang)) cua dung cong tac toan cao*.