Perhaps you should try some spelling variations:
trinh luan » trinh luat, trinh han, trinh toan
trinh quan » tinh quang, trinh luat, trinh han
hieu lang » chieu sang, hieu quang, nhieu tang
dung cong » dung trong
danh toan » manh toan, dan toan, dang toan
anh toan » manh toan, anh tuan, thanh toan
ho hieu » ho chieu, hoi hieu, nho hieu

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 hieu lang - hanh ((trinh luan) OR (trinh quan)) dung cong ((danh toan) OR (anh toan)) cau~.
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - hanh ((trinh luan) or (trinh quan)) dung cong ((danh toan) or (anh toan)) cau*.