Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hanh trinh » canh tranh, hanh chinh
hieu lang » chieu sang, hieu quang, nhieu tang
doi hieu » doi chieu, doc hieu, doi hien
trinh ve » trinh he, trinh va, trinh vi
ve nhung » va nhung, tu nhung
dan toan » van toan, dan than, manh toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi hieu lang - hanh trinh ve nhung cong ((dan toan) or (tinh toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - hanh trinh ve nhung cong ((dan toan) OR (tinh toan)) cau.
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - hanh trinh ve nhung cong ((dan toan) or (tinh toan)) cau*.