Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
khai sang » kha nang, nha sang, thai bang
khi sang » phi san, nha sang, thi song
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai toan
toan ban » van ban
tung ha » trung ha, dung ha, tang ha
tung ho » tuong ho, trung hoc, trung hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((khi sang) or (khai sang)) - thanh ((tung ha) OR (tung ho)) nhung cong tap toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((khi sang) OR (khai sang)) - thanh ((tung ha) OR (tung ho)) nhung cong tap toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((khi sang) or (khai sang)) - thanh ((tung ha) OR (tung ho)) nhung cong tap toan ban".
• Adding a wildcard symbol may retrieve word variants: doi ((khi sang) or (khai sang)) - thanh ((tung ha) OR (tung ho)) nhung cong tap toan ban*.