Perhaps you should try some spelling variations:
thuong cong » thong cong, thuong con, thuong dong
thieu tach » thien hach, chiet tach, chieu sach
hoc thieu » toc thieu, hoc hien
hoang van » hang va
dang van » hang va
cong tan » cong tac, cong san, cong thanh
tan van » tran van, tang van, luan van

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu tach - anh ((dang van) or (hoang van)) thuong cong tan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu tach - anh ((dang van) OR (hoang van)) thuong cong tan van ban*.