Perhaps you should try some spelling variations:
trinh thuat » trinh luat, trinh thiet, trinh chat
trinh thuc » trinh tu
hien tach » thien hach, chiet tach, vien bach
trinh thi » trinh tai, dinh thi, trinh tu
hang cong » dang cong, hang nong, bang cong
cong dan » cong san, cong tan, huong dan
dan van » dang van, doan van, dao van

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 - hanh ((((trinh thuat) OR (trinh thuc))) OR (trinh thi)) hang cong dan van ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien tach - hanh ((((trinh thuat) OR (trinh thuc))) or (trinh thi)) hang cong dan van ban~".
• Adding a wildcard symbol may retrieve word variants: hoc hien tach - hanh ((((trinh thuat) OR (trinh thuc))) or (trinh thi)) hang cong dan van ban*.