Perhaps you should try some spelling variations:
phuong cong » phuong dong, phong cong, phung cong
toan khoan » toan khoa, toan phan, toan hoat
doi chieu » doc hieu, doi chi, mot chieu
cong toan » cong tan, cong hoan, cong tuan
khoan cap » khoan cam, khan cap, khoa cap
ho chieu » theo chieu, hoc thieu, mot chieu
trung va » truong va, trang va, trung tam
trung ha » trung hoc, trung tam, trung cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doi chieu) or (ho chieu)) xanh - thanh ((trung va) OR (trung ha)) phuong cong toan khoan cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (ho chieu)) xanh - thanh ((trung va) OR (trung ha)) phuong cong toan khoan cap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) or (ho chieu)) xanh - thanh ((trung va) OR (trung ha)) phuong cong toan khoan cap".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (ho chieu)) xanh - thanh ((trung va) OR (trung ha)) phuong cong toan khoan cap*.