Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hien xanh » hien hanh, hien nhanh, chieu xanh
trang ha » trung ha, tang ha, trang cham
trang va » tran van, hang va
cong tap » cuong tap, cong tac, cong tan
doan cau » toan cau, doan dau, doan cap
toan tap » toan ban

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: hoc hien xanh - hanh ((trang ha) OR (trang va)) nhung cong tap ((doan cau) OR (toan tap))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien xanh - hanh ((trang ha) OR (trang va)) nhung cong tap ((doan cau) or (toan tap))~".
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - hanh ((trang ha) OR (trang va)) nhung cong tap ((doan cau) or (toan tap))*.