Perhaps you should try some spelling variations:
thanh trung » thanh tung
cong thanh » dong thanh, cong trinh, cong tan
trung tac » trung tam, trong tac, trung tai
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
doc kieu » cac kieu, doc viet, doi kien
tac dung » sach dung, xay dung, tin dung
do kiet » do viet, doi kien, don kien
san cau » van cau, ban cau, can cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((((doc kieu) or (do kiet))) or (doc hieu)) tinh - thanh trung tac dung cong thanh san cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((doc kieu) OR (do kiet))) OR (doc hieu)) tinh - thanh trung tac dung cong thanh san cau.
• Adding a wildcard symbol may retrieve word variants: ((((doc kieu) or (do kiet))) or (doc hieu)) tinh - thanh trung tac dung cong thanh san cau*.