Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
hien xanh » hien hanh, hien nhanh, chieu xanh
trong tap » trong thap, tong tap, trong tan
cua dung » cua dang, cua dong, cua rung
qua dung » quang dung, su dung, qua song
toan cau » toan ban, toan tap, toan tai
toan cao » toan ban, toan 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 hien xanh - hanh tranh ((cua dung) OR (qua dung)) trong tap ((toan cau) OR (toan cao))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien xanh - hanh tranh ((cua dung) OR (qua dung)) trong tap ((toan cau) or (toan cao))~".
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - hanh tranh ((cua dung) OR (qua dung)) trong tap ((toan cau) or (toan cao))*.