Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
thien hach » thien thanh
hien hanh » dieu hanh
hanh hang » thanh hang, hang hang, hanh han
dong cong » duong cong, dung cong, dang cong
cong san » cong tac
san phan » san pham, van phan, sat phan
va dong » van dong, ha dong, xa dong

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