Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
cua thong » cua thuong, cua khong, cua tong
thong bai » thong tai, nhung bai, thong xay
anh tang » anh bang, anh dang, anh nang
tang cua » mang cua, hang cua, tang luan
bai toan » bai tap
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 - anh tang cua thong thong bai toan cau~.
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - anh tang cua thong thong bai toan cau*.