Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
hieu lang » chieu sang, hieu quang, nhieu tang
tinh cang » tinh sang, tinh bang, tinh lang
dung cong » dung trong
cong vang » cong lang, cong quang, cong ngang
cang vat » dang vat, bang vat, hang va
vat dung » van dung, va dung, viet dung
toan cao » toan ban
toan tap » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hieu manh) or (hieu lang)) - tinh cang vat dung cong vang ((toan cao) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (hieu lang)) - tinh cang vat dung cong vang ((toan cao) OR (toan tap)).
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) or (hieu lang)) - tinh cang vat dung cong vang ((toan cao) or (toan tap))*.