Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, nhieu tang
hanh trang » canh tranh, hanh trinh, minh trang
thong cong » trong cong, tong cong, thong thong
hieu lang » hieu quang, nhieu tang, hieu van
va thong » va thuong, va phuong, he thong
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: thien ((hieu lang) OR (chieu sang)) - ((hanh trang) or (thanh trung)) va thong cong dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thien ((hieu lang) OR (chieu sang)) - ((hanh trang) OR (thanh trung)) va thong cong dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thien ((hieu lang) OR (chieu sang)) - ((hanh trang) or (thanh trung)) va thong cong dan toan cao".
• Adding a wildcard symbol may retrieve word variants: thien ((hieu lang) OR (chieu sang)) - ((hanh trang) or (thanh trung)) va thong cong dan toan cao*.