Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
doi hieu » doi chieu, doc hieu, doi hien
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
toan cao » toan ban, toan tap
tung he » tung ho, tang he, tung le
dung he » dung cho

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi hieu lang - thanh ((tung he) OR (dung he)) thong cong tan toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu lang - thanh ((tung he) OR (dung he)) thong cong tan toan cao".
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - thanh ((tung he) OR (dung he)) thong cong tan toan cao*.