Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hien hach » thien hach, hien hanh, hien nhanh
trinh cua » trinh luat, trinh quan, trinh luan
tinh cua » sinh cua, tinh chat, tranh cua
cong dan » cong san, cong tan, huong dan
toan cao » toan tap
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 hien hach - hanh ((trinh cua) OR (tinh cua)) thong cong dan ((toan cao) OR (toan ban))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien hach - hanh ((trinh cua) or (tinh cua)) thong cong dan ((toan cao) OR (toan ban))~".
• Adding a wildcard symbol may retrieve word variants: hoc hien hach - hanh ((trinh cua) or (tinh cua)) thong cong dan ((toan cao) OR (toan ban))*.