Perhaps you should try some spelling variations:
dong thieu » dong trieu, dong tieu, dong thi
dong hieu » dung hieu, dong trieu, doc hieu
hanh tang » hanh trang, anh tang, hanh mang
dong cong » duong cong, dung cong, dang cong
dan khoan » dan khoa, dai khoang, toan khoan
khoan cam » khoa cam, khoan va, phan cam
tang cua » mang cua, hang cua, tang luan
cua dong » chua dong, cua cong, cua dang
cong dan » cong san, cong tan, huong dan

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((dong thieu) OR (dong hieu)) tinh - hanh tang cua dong cong dan khoan cam~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((dong thieu) OR (dong hieu)) tinh - hanh tang cua dong cong dan khoan cam".
• Adding a wildcard symbol may retrieve word variants: ((dong thieu) OR (dong hieu)) tinh - hanh tang cua dong cong dan khoan cam*.