Perhaps you should try some spelling variations:
dong cong » duong cong, dung cong, dang cong
khoan cam » khoa cam, phan cam, thuan cam
tang cua » hang cua, tang luan, thong cua
mang cua » manh cua, dung cua, ban cua
cong dan » cong san, cong tan, huong dan
khoan va » doan va, khoa ma, nhan va
trieu » thieu, trien, tieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: dong trieu tinh - hanh ((tang cua) or (mang cua)) dong cong dan ((khoan cam) OR (khoan va))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: dong trieu tinh - hanh ((tang cua) OR (mang cua)) dong cong dan ((khoan cam) OR (khoan va)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "dong trieu tinh - hanh ((tang cua) or (mang cua)) dong cong dan ((khoan cam) OR (khoan va))".
• Adding a wildcard symbol may retrieve word variants: dong trieu tinh - hanh ((tang cua) or (mang cua)) dong cong dan ((khoan cam) OR (khoan va))*.