Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
hanh sang » anh sang, hanh mang, lanh sang
trong van » trong cac
hanh san » thanh san, khach san, thanh son
van quan » van ban
quan cau » quang cao, toan cau, quan ha
va dung » van dung, va duong, vat dung

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 sang) OR (hanh san)) va dung trong van quan cau~.
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - ((hanh sang) or (hanh san)) va dung trong van quan cau*.