Perhaps you should try some spelling variations:
thiet thanh » thi thanh, viet thanh, them thanh
thien thanh » tien thanh, thi thanh, hien hanh
thanh thang » nhanh thang, thanh thanh, thanh hang
thang dam » thang tam, thanh dam, chang dam
nang cong » nang song, dang cong, bang cong
dam nang » cam nang, da nang, dai nang
cong dan » cong san, cong tan, huong dan
dan chan » dan gian, dan ca, van chat
chan cau » phan cau, can cau, chinh cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thiet thanh) or (thien thanh)) - thanh thang dam nang cong dan chan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet thanh) OR (thien thanh)) - thanh thang dam nang cong dan chan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet thanh) or (thien thanh)) - thanh thang dam nang cong dan chan cau*.