Perhaps you should try some spelling variations:
trinh quan » tinh quang, trinh luat, trinh han
hieu lang » chieu sang, hieu quang, nhieu tang
hang cong » dang cong, hang nong, bang cong
cong tan » cong tac, cong san, cong thanh
he hieu » he nhieu, he dieu, de hieu
tan ban » toan ban, tang ban, van ban
ban cau » bang cau, ban can, van cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: he hieu lang - canh ((trinh quan) or (sinh vat)) hang cong tan ban cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: he hieu lang - canh ((trinh quan) OR (sinh vat)) hang cong tan ban cau.
• Adding a wildcard symbol may retrieve word variants: he hieu lang - canh ((trinh quan) or (sinh vat)) hang cong tan ban cau*.