Perhaps you should try some spelling variations:
diep quang » dinh quang
hieu quan » hieu qua, lieu quan, thien quan
trinh han » trinh quan
tong cong » trong cong, cong cong, dung cong
tan thanh » tran thanh, tang thanh, toan thanh
thanh cac » hanh cac, thanh bac, thanh ca
trinh he » trinh hoa, trinh thi, trinh ky
cong tan » cong tac, cong san, cong thanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: thien ((diep quang) or (hieu quan)) - hanh ((trinh he) or (trinh han)) tong cong tan thanh cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thien ((diep quang) OR (hieu quan)) - hanh ((trinh he) OR (trinh han)) tong cong tan thanh cac.
• Adding a wildcard symbol may retrieve word variants: thien ((diep quang) or (hieu quan)) - hanh ((trinh he) or (trinh han)) tong cong tan thanh cac*.