Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
cong quang » luong quang, thong quang, duong quang
hieu xanh » chieu xanh, hieu manh, hieu nganh
trung dap » trung cap, trung dam, trung lap
trung dai » truong dai, truong dao, trung tam
doc hieu » toc thieu, hoc thieu, hoc hien
tuan cau » quan cau, tuan cu, thuan cam
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 - hanh ((trung dap) OR (trung dai)) nhung cong quang ((tuan cau) or (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - hanh ((trung dap) OR (trung dai)) nhung cong quang ((tuan cau) OR (toan cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - hanh ((trung dap) OR (trung dai)) nhung cong quang ((tuan cau) or (toan cau))".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh ((trung dap) OR (trung dai)) nhung cong quang ((tuan cau) or (toan cau))*.