Perhaps you should try some spelling variations:
lieu tinh » trieu tinh, diep tinh, bien tinh
hang cong » dang cong, hang nong, bang cong
cong cac » cuong cac, cong tac, cong cau
cac hang » cac dang, cac bang, cac lang
van toan » van tuan, van tan, van thanh
bai toan » bai tap
ho lieu » so lieu, co lieu, ho kieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho lieu tinh - thanh cong cac hang cong ((van toan) or (bai toan)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho lieu tinh - thanh cong cac hang cong ((van toan) OR (bai toan)) tap.
• Adding a wildcard symbol may retrieve word variants: ho lieu tinh - thanh cong cac hang cong ((van toan) or (bai toan)) tap*.