Perhaps you should try some spelling variations:
vien thanh » viet thanh, tien thanh, dien thanh
hanh trung » thanh trung, hanh trang, manh trung
trung tuan » trung thanh, trung tam, tran tuan
hieu xanh » chieu xanh, hieu manh, hieu nganh
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

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 xanh) or (vien thanh)) - hanh trung tuan ((hang cong) OR (dang cong)) dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu xanh) OR (vien thanh)) - hanh trung tuan ((hang cong) OR (dang cong)) dan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu xanh) or (vien thanh)) - hanh trung tuan ((hang cong) OR (dang cong)) dan toan cau".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu xanh) or (vien thanh)) - hanh trung tuan ((hang cong) OR (dang cong)) dan toan cau*.