Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
hien xanh » hien hanh, hien nhanh, chieu xanh
tranh cua » doanh cua, manh cua
trong tap » trong thap, tong tap, trong tan
cua dung » cua dang, cua dong, qua dung
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.

• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien xanh - hanh tranh cua dung trong tap ((toan cau) OR (toan cao))~".
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - hanh tranh cua dung trong tap ((toan cau) OR (toan cao))*.