Perhaps you should try some spelling variations:
trung tuan » trung thanh, trung tam, tran tuan
khong cong » thong cong, khong cang, chong cong
thiet anh » thuyet anh, thien danh, thich anh
thien anh » thien danh, tien anh, thien thanh
trung cap » truong cao, trung tam
cong tan » cong tac, cong san, cong thanh
tan khan » tan khang, tan nhan, toan khoan
khan cap » khan ap, than cap, khoan cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thiet anh) OR (thien anh)) - thanh ((trung cap) or (trung tuan)) khong cong tan khan cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet anh) OR (thien anh)) - thanh ((trung cap) OR (trung tuan)) khong cong tan khan cap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet anh) OR (thien anh)) - thanh ((trung cap) or (trung tuan)) khong cong tan khan cap".
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet anh) OR (thien anh)) - thanh ((trung cap) or (trung tuan)) khong cong tan khan cap*.