Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
hanh tang » hanh trang, anh tang, hanh tung
hanh mang » nhanh mang, hanh trang, nhanh lang
cua tong » cua cong, cua nong, cua song
cua dong » chua dong, cua cong, cua dang
cong tan » cong tac, cong san, cong thanh
tan than » tan thanh, tan tran, ban than
than cau » toan cau, phan cau, than cap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien xanh - ((hanh tang) OR (hanh mang)) ((cua tong) or (cua dong)) cong tan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien xanh - ((hanh tang) OR (hanh mang)) ((cua tong) OR (cua dong)) cong tan than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien xanh - ((hanh tang) OR (hanh mang)) ((cua tong) or (cua dong)) cong tan than cau".
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - ((hanh tang) OR (hanh mang)) ((cua tong) or (cua dong)) cong tan than cau*.