Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
trinh luan » trinh luat, trinh quan, trinh han
hang hang » nang hang, cang thang, hung thang
hang manh » hoang manh, hung manh, dang manh
manh toan » thanh toan, anh tuan, tinh toan
doc hieu » toc thieu, hoc thieu, hoc hien
tinh cua » trinh cua, sinh cua, tinh chat
toan ban » van ban

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu quang - hanh ((trinh luan) or (tinh cua)) hang hang manh toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu quang - hanh ((trinh luan) OR (tinh cua)) hang hang manh toan ban*.