Perhaps you should try some spelling variations:
hanh phang » khanh phong, nhanh thang, thanh thang
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
hanh phan » thanh phan, anh phan, hanh han
doi hieu » doi chieu, doc hieu, doi hien
va thong » va thuong, va phuong, he thong
cong dan » cong san, cong tan, huong dan
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: doi hieu lang - ((hanh phang) or (hanh phan)) va thong cong dan ((toan cao) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - ((hanh phang) OR (hanh phan)) va thong cong dan ((toan cao) OR (toan tap)).
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - ((hanh phang) or (hanh phan)) va thong cong dan ((toan cao) or (toan tap))*.