Perhaps you should try some spelling variations:
thuyet tinh » thuyet trinh, thuyet kinh, thuyet dinh
hoc thuyet » hoc chuyen
hung quang » dung quang, hong quang, vung quang
cong quang » luong quang, thong quang, duong quang
trong tan » trong quan, trong cac, trong ca
tan toan » tan tran, tap toan, van toan
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 thuyet tinh - thanh ((hung quang) or (cong quang)) dung trong tan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thuyet tinh - thanh ((hung quang) OR (cong quang)) dung trong tan toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc thuyet tinh - thanh ((hung quang) or (cong quang)) dung trong tan toan cao*.