Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
thong cong » trong cong, tong cong, thong thong
thanh phan » thanh pho, thanh san, thanh toan
hanh tang » hanh trang, anh tang, hanh mang
tan thanh » tran thanh, tang thanh, toan thanh
hieu cac » hieu luc, hieu va, hieu van
va thong » va thuong, va phuong, he thong
cong tan » cong tac, cong san, cong thanh
tang va » trang va, tang van, thang va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((hieu cac) or (chieu sach)) - hanh tang va thong cong tan thanh phan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((hieu cac) OR (chieu sach)) - hanh tang va thong cong tan thanh phan*.