Perhaps you should try some spelling variations:
theo hieu » theo chieu, theo tieu, thien hieu
hieu lang » chieu sang, hieu quang, nhieu tang
thong cua » thong quan, thong tu, huong cua
trong tac » trong cac, tuong tac, trong tan
mang cua » manh cua, dung cua, ban cua
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: theo hieu lang - hanh ((mang cua) or (thong cua)) dung trong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo hieu lang - hanh ((mang cua) OR (thong cua)) dung trong tac toan cau.
• Adding a wildcard symbol may retrieve word variants: theo hieu lang - hanh ((mang cua) or (thong cua)) dung trong tac toan cau*.