Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hoc hieu » hoc thieu, hoc hien, doc hieu
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan ban » van ban
manh va » hanh va, anh va, lanh va
minh va » tinh va, sinh va, sinh vat

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc hieu) OR (toc thieu)) lang - hanh ((manh va) OR (minh va)) nhung cong dan toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc hieu) or (toc thieu)) lang - hanh ((manh va) OR (minh va)) nhung cong dan toan ban~".
• Adding a wildcard symbol may retrieve word variants: ((hoc hieu) or (toc thieu)) lang - hanh ((manh va) OR (minh va)) nhung cong dan toan ban*.