Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
nhung cong » dung cong, thong cong, hang cong
hieu cach » hieu cac, chieu sach, hieu ca
trung cua » truong cua, trung tuan, dung cua
trung cap » truong cao, trung tam
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thien hach) or (hieu cach)) - thanh ((trung cua) or (trung cap)) nhung cong san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thien hach) OR (hieu cach)) - thanh ((trung cua) OR (trung cap)) nhung cong san toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((thien hach) or (hieu cach)) - thanh ((trung cua) or (trung cap)) nhung cong san toan cau*.