Perhaps you should try some spelling variations:
thanh trung » thanh tung
khong cong » thong cong, chong cong, khong con
khong cang » thong cong, hong bang, khong dung
hiem ngan » kim ngan, viem gan
doc hiem » doc hieu, hoc hien, doc viet
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hiem ngan - thanh trung tam ((khong cong) or (khong cang)) tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hiem ngan - thanh trung tam ((khong cong) OR (khong cang)) tac toan cau.
• Adding a wildcard symbol may retrieve word variants: doc hiem ngan - thanh trung tam ((khong cong) or (khong cang)) tac toan cau*.