Perhaps you should try some spelling variations:
trinh thuat » trinh luat, trinh thiet, trinh thuc
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 dang » cong dong, cong dan, cong dung
dang van » hoang van, hang va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien tach - hanh ((trinh thuat) or (trinh thi)) hang cong dang van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien tach - hanh ((trinh thuat) OR (trinh thi)) hang cong dang van ban.
• Adding a wildcard symbol may retrieve word variants: hoc hien tach - hanh ((trinh thuat) or (trinh thi)) hang cong dang van ban*.