Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
thiet hach » thien hach, thuyet hach, thiet hai
cong quang » luong quang, thong quang, duong quang
hoc thiet » hoc thieu, hoc thuyet, hoc hien
hanh tran » hanh trang, thanh tran, hanh tram
van thong » van thuong, van phong, va thong
tranh ban » trinh ban, tranh hang, tranh luan
trinh san » trinh han, trinh quan, trinh toan
tran van » luan van

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thiet hach - hanh tran van thong cong quang ((tranh ban) or (trinh san))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet hach - hanh tran van thong cong quang ((tranh ban) OR (trinh san)).
• Adding a wildcard symbol may retrieve word variants: hoc thiet hach - hanh tran van thong cong quang ((tranh ban) or (trinh san))*.