Perhaps you should try some spelling variations:
chiet tach » chieu sach
nhieu tang » chieu sang, hieu lang, nhiet nang
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, hang cong
trinh ve » trinh he, trinh va, trinh vi
ve nhung » va nhung, tu nhung
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((chiet tach) or (nhieu tang)) - hanh trinh ve nhung cong ((dan toan) OR (dan than)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chiet tach) OR (nhieu tang)) - hanh trinh ve nhung cong ((dan toan) OR (dan than)) tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chiet tach) or (nhieu tang)) - hanh trinh ve nhung cong ((dan toan) OR (dan than)) tap".
• Adding a wildcard symbol may retrieve word variants: theo ((chiet tach) or (nhieu tang)) - hanh trinh ve nhung cong ((dan toan) OR (dan than)) tap*.