Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, nhieu tang, hieu van
hanh mang » nhanh mang, hanh trang, nhanh lang
tan toan » tan tran, tap toan, dan toan
van toan » van tuan, van tan, van thanh
mang va » mang vua, hang va, bang va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu lang) OR (hieu quang)) - hanh mang va nhung cong ((tan toan) or (van toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (hieu quang)) - hanh mang va nhung cong ((tan toan) OR (van toan)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) OR (hieu quang)) - hanh mang va nhung cong ((tan toan) or (van toan)) cao".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) OR (hieu quang)) - hanh mang va nhung cong ((tan toan) or (van toan)) cao*.