Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
thong cong » trong cong, tong cong, thong thong
trinh vat » trinh van, trinh luat, sinh vat
dung cong » dung trong
hien anh » hien hanh, thien anh, dien anh
than cap » khan cap, thanh lap, thanh cac
phan lap » phan dau

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 hien anh - hanh trinh vat ((thong cong) OR (dung cong)) dan ((than cap) OR (phan lap))~.
• Adding a wildcard symbol may retrieve word variants: hoc hien anh - hanh trinh vat ((thong cong) or (dung cong)) dan ((than cap) or (phan lap))*.