Perhaps you should try some spelling variations:
thanh tung » thanh cong
duong cong » dung cong, luong cong, duong trong
chu manh » ho manh, chu han, thu minh
va duong » van duong, va tuong, va huong
bai toan » bai tap
ban than » ban thanh, van thanh, ban hang
chu van » cuu van, chu han
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: theo ((chu manh) or (chu van)) - thanh tung va duong cong ((bai toan) or (ban than)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chu manh) OR (chu van)) - thanh tung va duong cong ((bai toan) OR (ban than)) ban.
• Adding a wildcard symbol may retrieve word variants: theo ((chu manh) or (chu van)) - thanh tung va duong cong ((bai toan) or (ban than)) ban*.