Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
trung tuan » trung thanh, trung tam, tran tuan
hien tach » chiet tach, vien bach, hien hanh
trung cua » truong cua, trung cap, dung cua
dung cong » dung trong
cong van » cong vang, cong san, song van
van tan » van tuan, van ban, van tai
tan cau » toan cau, van cau, tan ca

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 tach) OR (thien hach)) - hanh ((trung cua) OR (trung tuan)) dung cong van tan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien tach) or (thien hach)) - hanh ((trung cua) OR (trung tuan)) dung cong van tan cau~".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien tach) or (thien hach)) - hanh ((trung cua) OR (trung tuan)) dung cong van tan cau*.