Perhaps you should try some spelling variations:
thieu xanh » hieu manh, thien anh, thien danh
chieu xanh » chieu sach, chieu sang, chieu tinh
tang quan » tang luan, tong quan, thong quan
nang quan » ban quan, nang suat
dung cong » dung trong
cong van » cong vang, cong san, song van
van quan » van ban
quan cau » quang cao, toan cau, quan ha

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 ((thieu xanh) OR (chieu xanh)) - hanh ((tang quan) OR (nang quan)) dung cong van quan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) or (chieu xanh)) - hanh ((tang quan) OR (nang quan)) dung cong van quan cau~".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) or (chieu xanh)) - hanh ((tang quan) OR (nang quan)) dung cong van quan cau*.