Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien danh
nhung cong » dung cong, thong cong, hang cong
thien anh » thien danh, tien anh, thien thanh
tang luan » dung luan
tang cua » mang cua, hang cua, thong cua
cong tac » cong ty
tac tran » tan tran, tac trai, tac tren
tran cau » tran chau, toan cau, ran cau

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) OR (thien anh)) - hanh ((tang cua) OR (tang luan)) nhung cong tac tran cau~".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) OR (thien anh)) - hanh ((tang cua) OR (tang luan)) nhung cong tac tran cau*.