Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
tranh cua » doanh cua, manh cua
cua trung » cua truong, xuan trung, cua nhung
tuong dan » huong dan, xuong dan, truong dai
tung dan » huong dan, trung dai, dung dat
dung dan » dung dat, dung san, huong dan
toan cau » 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 - canh tranh cua trung ((((tuong dan) OR (tung dan))) OR (dung dan)) toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien xanh - canh tranh cua trung ((((tuong dan) OR (tung dan))) or (dung dan)) toan cau~".
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - canh tranh cua trung ((((tuong dan) OR (tung dan))) or (dung dan)) toan cau*.