Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
anh trong » anh thuong, dinh trong, lang trong
dung cong » dung trong
tran tuan » tran xuan, tran quang, tran thanh
cac dung » cach dung, cac duong, tac dung
cong san » cong tac
tran tan » tran van, tran thanh, trang tuan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien xanh - anh trong cac dung cong san ((tran tan) or (tran tuan))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien xanh - anh trong cac dung cong san ((tran tan) OR (tran tuan)).
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - anh trong cac dung cong san ((tran tan) or (tran tuan))*.