Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
hanh hang » thanh hang, hang hang, hanh han
hai thong » hai thuong, hai phong, hai trong
thong tac » thong cac, tuong tac, thong tai
hang hai » hoang hai, hang tai, thanh hai
tac toan » tap toan, tam toan, hach 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 hang hai thong thong tac toan cau~.
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - hanh hang hai thong thong tac toan cau*.