Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hanh tang » hanh trang, anh tang, hanh mang
theo chu » theo chieu, cho chu, chao chu
cong tan » cong tac, cong san, cong thanh
toan cau » toan ban, toan tap, toan tai
toan cao » toan ban, toan tap
tang va » trang va, tang van, thang 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: ((theo chu) OR (theo tieu)) sach - hanh tang va nhung cong tan ((toan cau) OR (toan cao))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chu) or (theo tieu)) sach - hanh tang va nhung cong tan ((toan cau) OR (toan cao))~".
• Adding a wildcard symbol may retrieve word variants: ((theo chu) or (theo tieu)) sach - hanh tang va nhung cong tan ((toan cau) OR (toan cao))*.