Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
chieu sach » chinh sach, chiet tach, chieu sang
hanh han » hanh nhan, hanh phan, hanh san
tai dong » thai dong, tai cong, tai tong
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
phan cau » phan dau, phan cac, phan tu
han tai » hang tai, nhan tai, van 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 han tai dong ((cong dan) OR (cong san)) phan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thien hach) or (chieu sach)) - hanh han tai dong ((cong dan) OR (cong san)) phan cau~".
• Adding a wildcard symbol may retrieve word variants: hoc ((thien hach) or (chieu sach)) - hanh han tai dong ((cong dan) OR (cong san)) phan cau*.