Perhaps you should try some spelling variations:
trinh quan » tinh quang, trinh luat, trinh han
trinh qua » trinh cua, trinh quang, trinh luat
dung cong » dung trong
ho chieu » theo chieu, hoc thieu, doi chieu
cong van » cong vang, cong san, song van
van toan » van tuan, van tan, van thanh
toan cau » 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: ((ho chieu) OR (hoc hien)) xanh - hanh ((trinh qua) OR (trinh quan)) dung cong van toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (hoc hien)) xanh - hanh ((trinh qua) OR (trinh quan)) dung cong van toan cau~".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (hoc hien)) xanh - hanh ((trinh qua) OR (trinh quan)) dung cong van toan cau*.