Perhaps you should try some spelling variations:
hoc thieu » toc thieu, hoc hien
hanh tang » hanh trang, anh tang, hanh mang
trong bai » trong ban, thong bai, trong hai
doc hieu » toc thieu, hoc hien
tang cua » mang cua, hang cua, tang luan
cua dung » cua dang, cua dong, qua dung
bai toan » bai tap
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: ((doc hieu) or (hoc thieu)) xanh - hanh tang cua dung trong bai toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (hoc thieu)) xanh - hanh tang cua dung trong bai toan cao.
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (hoc thieu)) xanh - hanh tang cua dung trong bai toan cao*.