Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
tran tuan » tran xuan, tran quang, tran thanh
trong dan » trong dang, trong san, trong tan
doc hieu » toc thieu, hoc thieu, hoc hien
tang cua » mang cua, hang cua, tang luan
dan toan » van toan, dan than, manh 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: doc hieu manh - hanh ((tang cua) or (tran tuan)) dung trong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu manh - hanh ((tang cua) OR (tran tuan)) dung trong dan toan cau.
• Adding a wildcard symbol may retrieve word variants: doc hieu manh - hanh ((tang cua) or (tran tuan)) dung trong dan toan cau*.