Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu xanh » chieu sach, chieu sang, chieu tinh
chua nang » chua xang, kha nang, cuu nang
khoan cam » khoa cam, khoan va, phan cam
ho chieu » theo chieu, hoc thieu, doi chieu
cong ban » cong bang, cong tan, cong dan
cong san » cong tac
chuc » thuc, chu, phuc

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: ho chieu xanh - thanh trung ((chua nang) OR (chuc nang)) ((cong ban) OR (cong san)) khoan cam~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho chieu xanh - thanh trung ((chua nang) OR (chuc nang)) ((cong ban) or (cong san)) khoan cam~".
• Adding a wildcard symbol may retrieve word variants: ho chieu xanh - thanh trung ((chua nang) OR (chuc nang)) ((cong ban) or (cong san)) khoan cam*.