Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
chieu sach » chinh sach, chiet tach, chieu sang
dong cong » duong cong, dung cong, dang cong
hanh san » thanh san, khach san, thanh son
tai dong » thai dong, tai cong, tai tong
cong san » cong tac
phan cau » phan dau, phan cac, phan lap
san tai » sang tai, van tai, han tai

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 ((thien hach) OR (chieu sach)) - hanh san tai dong cong san ((phan cau) OR (phan tu))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thien hach) or (chieu sach)) - hanh san tai dong cong san ((phan cau) OR (phan tu))~".
• Adding a wildcard symbol may retrieve word variants: hoc ((thien hach) or (chieu sach)) - hanh san tai dong cong san ((phan cau) OR (phan tu))*.