Perhaps you should try some spelling variations:
phuong cham » phuong phap
phuong thao » phuong phap, phuong thuc
chieu tach » chiet tach, chieu sach, chiu trach
phuong la » phuong lan, phuong tay, phuong mai
trong van » trong cac
ho chieu » theo chieu, hoc thieu, doi chieu
van toan » van tuan, van tan, van thanh
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: ho chieu tach - thanh ((((phuong cham) OR (phuong thao))) or (phuong la)) dung trong van toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu tach - thanh ((((phuong cham) OR (phuong thao))) OR (phuong la)) dung trong van toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho chieu tach - thanh ((((phuong cham) OR (phuong thao))) or (phuong la)) dung trong van toan cau".
• Adding a wildcard symbol may retrieve word variants: ho chieu tach - thanh ((((phuong cham) OR (phuong thao))) or (phuong la)) dung trong van toan cau*.