Perhaps you should try some spelling variations:
chieu sach » chinh sach, chieu sang, chieu xanh
trinh van » trinh han, trinh quan, trinh toan
dung cong » dung trong
trinh ve » trinh he, trinh va, trinh vi
cong van » cong vang, cong san, song van
van toan » van tuan, van tan, van thanh
toan cao » toan ban, toan tap

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: doi ((chieu sach) OR (chiet tach)) - canh ((trinh ve) OR (trinh van)) dung cong van toan cao~.
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sach) or (chiet tach)) - canh ((trinh ve) or (trinh van)) dung cong van toan cao*.