Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
tinh sang » tinh quang, tinh trang, trinh san
cua nhung » va nhung
anh tang » anh bang, anh dang, anh nang
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
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: hoc hien xanh - ((anh tang) or (tinh sang)) cua nhung ((cong dan) or (cong san)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien xanh - ((anh tang) OR (tinh sang)) cua nhung ((cong dan) OR (cong san)) toan tap.
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - ((anh tang) or (tinh sang)) cua nhung ((cong dan) or (cong san)) toan tap*.