Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hieu tinh » chieu tinh, lieu tinh, kieu tinh
doc hieu » toc thieu, hoc thieu, hoc hien
sinh lao » sinh lam, sinh ly, sinh vat
tinh lao » dinh lam, tinh nam, tinh va
cong dan » cong san, cong tan, huong dan
toan cau » toan cao, toan ban, toan tap

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: doc hieu tinh - hanh ((sinh lao) OR (tinh lao)) thong cong dan ((toan cau) OR (van ban))~.
• Adding a wildcard symbol may retrieve word variants: doc hieu tinh - hanh ((sinh lao) or (tinh lao)) thong cong dan ((toan cau) or (van ban))*.