Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
nhung cong » dung cong, thong cong, hang cong
hieu cach » hieu cac, chieu sach, hieu ca
trinh van » trinh han, trinh quan, trinh toan
tranh va » tranh van, trang va, trinh va
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan ban » van ban

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 cach) OR (thien hach)) - hanh ((tranh va) OR (trinh van)) nhung cong dan toan ban~.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu cach) or (thien hach)) - hanh ((tranh va) or (trinh van)) nhung cong dan toan ban*.