Perhaps you should try some spelling variations:
thien thanh » tien thanh, thi thanh, hien hanh
tien manh » tien anh, tien thanh, tieng anh
anh hoang » thanh hoang, minh hoang, tnhh hoang
trong van » trong cac
hoang su » hoang tu, hoang vu, hoang du
van toan » van tuan, van tan, van thanh
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: hoc ((tien manh) or (thien thanh)) - anh hoang su dung trong van toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((tien manh) OR (thien thanh)) - anh hoang su dung trong van toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((tien manh) or (thien thanh)) - anh hoang su dung trong van toan cau*.