Perhaps you should try some spelling variations:
thinh sach » chinh sach, tinh sach, sinh sach
thai trien » thai tren, phat trien, thai phien
trien cong » thien cong
hanh tang » hanh trang, anh tang, hanh mang
tang thai » trang thai, tang tai, tang thi
dan toan » dan than, manh toan, xuan toan
van toan » van tuan, van tan, van thanh
tien » tieng, bien, vien

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: tien thinh sach - hanh tang thai trien cong ((dan toan) OR (van toan)) cao~.
• Adding a wildcard symbol may retrieve word variants: tien thinh sach - hanh tang thai trien cong ((dan toan) or (van toan)) cao*.