Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
chieu sang » chieu sach, chieu xanh, hieu lang
hieu manh » chieu xanh, hieu nganh, dieu hanh
cua dung » cua dang, cua dong, cua rung
qua dung » quang dung, su dung, qua song
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than tap » toan tap, han tap, phan tap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (chieu sang)) - hanh tranh ((cua dung) OR (qua dung)) cong dan than tap~.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) or (chieu sang)) - hanh tranh ((cua dung) or (qua dung)) cong dan than tap*.