Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
chieu sang » chieu sach, chieu xanh, hieu lang
thong cong » trong cong, tong cong, thong thong
trang va » hang va
tran van » luan van
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
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: hoc ((thieu xanh) or (chieu sang)) - hanh ((trang va) OR (tran van)) thong cong dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (chieu sang)) - hanh ((trang va) OR (tran van)) thong cong dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) or (chieu sang)) - hanh ((trang va) OR (tran van)) thong cong dan toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) or (chieu sang)) - hanh ((trang va) OR (tran van)) thong cong dan toan cao*.