Perhaps you should try some spelling variations:
thieu tach » chiet tach, chieu sach, hieu cach
thien hach » thien thanh, hien hanh
thanh dung » thanh duong, thanh tung, thanh hung
nang cong » nang song, dang cong, bang cong
tan thong » toan thong, tran thong, tao thong
thong cac » trong cac, phong cach, thong cua
dung van » duong van, dung va, dang van
van nang » van quang, van ban, van dong
cong tan » cong tac, cong san, cong thanh

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) or (thien hach)) - thanh dung van nang cong tan thong cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu tach) OR (thien hach)) - thanh dung van nang cong tan thong cac*.