Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu quang » thieu quang, hieu quan, hieu qua
hieu lang » chieu sang, nhieu tang, hieu van
trung cua » truong cua, trung tuan, trung cap
cong cong » cong dong, trong cong, dung cong
cong vang » cong lang, cong quang, cong ngang
vang tang » vang trang, van tang, cang thang
tang ban » tang bang, tiang ban, tang van

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 lang) or (hieu quang)) - thanh trung cua cong cong vang tang ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu lang) OR (hieu quang)) - thanh trung cua cong cong vang tang ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu lang) or (hieu quang)) - thanh trung cua cong cong vang tang ban*.