Perhaps you should try some spelling variations:
thuong dong » phuong dong, tuong dong, chuong dong
thuong cong » thong cong, thuong con, truong cong
thanh tung » thanh cong
hieu lang » chieu sang, hieu quang, nhieu tang
tan thanh » tran thanh, tang thanh, toan thanh
hoc hieu » hoc thieu, hoc hien, doc hieu
tan than » tan tran, ban than, tam than
tung va » trung va, tuong va, dung va

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu lang - thanh tung va ((thuong cong) OR (thuong dong)) ((tan than) or (tan thanh)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - thanh tung va ((thuong cong) OR (thuong dong)) ((tan than) OR (tan thanh)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu lang - thanh tung va ((thuong cong) OR (thuong dong)) ((tan than) or (tan thanh)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - thanh tung va ((thuong cong) OR (thuong dong)) ((tan than) or (tan thanh)) cau*.