Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
anh quang » anh xquang, anh quan, nhanh quang
vat dung » van dung, viet dung, mat duong
cong van » cong vang, cong san, song van
van toan » van tuan, van tan, van thanh
toan cau » toan cao, toan ban, toan tap
va dung » van dung, va duong, va ung

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 - anh quang ((va dung) OR (vat dung)) cong van toan cau~".
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - anh quang ((va dung) OR (vat dung)) cong van toan cau*.