Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
van hoang » van hoan, quan hoang, tran hoang
lang cong » bang cong, hang cong, lang dong
dang cong » dung cong
toc hieu » toc thieu, doc hieu, hoc thieu
tran van » luan van
sat phan » sat nhan, vat phan, xuat phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc hieu manh - tran van hoang ((lang cong) or (dang cong)) sat phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc hieu manh - tran van hoang ((lang cong) OR (dang cong)) sat phan tu*.