Perhaps you should try some spelling variations:
trinh thuat » trinh thiet, trinh thuc, trinh chat
dung cong » dung trong
khi sinh » ki sinh, khoe sinh, phai sinh
thi sinh » thai sinh, thi minh, thi hinh
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((khi sinh) or (thi sinh)) - hanh ((trinh thuat) OR (trinh luat)) dung cong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((khi sinh) OR (thi sinh)) - hanh ((trinh thuat) OR (trinh luat)) dung cong dan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((khi sinh) or (thi sinh)) - hanh ((trinh thuat) OR (trinh luat)) dung cong dan toan cau".
• Adding a wildcard symbol may retrieve word variants: doi ((khi sinh) or (thi sinh)) - hanh ((trinh thuat) OR (trinh luat)) dung cong dan toan cau*.