Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
tranh cua » doanh cua
dung tong » dung trong, dung thong, dung cong
manh cua » doanh cua, ban cua
tong tap » tuong tac, trong tan, cong tac
tap toan » tap doan, tap quan, bai toan
toan cau » toan cao, toan ban, toan tap

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 ((tranh cua) or (manh cua)) dung tong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien xanh - hanh ((tranh cua) OR (manh cua)) dung tong tap toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - hanh ((tranh cua) or (manh cua)) dung tong tap toan cau*.