Perhaps you should try some spelling variations:
thanh dung » thanh duong, thanh tung, thanh hung
thong cong » trong cong, tong cong, thong thong
cua thong » cua thuong, cua khong, cua tong
hoc hieu » hoc thieu, hoc hien, hoc dieu
doc hieu » toc thieu, hoc thieu, hoc hien
dung cua » dung luan, dung cho
cong dan » cong san, cong tan, huong dan
dan chan » dan gian, dan ca, van chat
chan cau » phan cau, can cau, chinh cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc hieu) or (doc hieu)) manh - thanh dung cua thong cong dan chan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc hieu) OR (doc hieu)) manh - thanh dung cua thong cong dan chan cau.
• Adding a wildcard symbol may retrieve word variants: ((hoc hieu) or (doc hieu)) manh - thanh dung cua thong cong dan chan cau*.