Perhaps you should try some spelling variations:
phuong giang » huong giang, phuong hoang, truong giang
phuong cang » phuong bang, phuong hoang, phuong quang
thanh tung » thanh cong
doi chieu » doc hieu, doi chi, mot chieu
ho chieu » theo chieu, hoc thieu, mot chieu
tung cua » trung cua, tuong cua, dung cua
tap toan » tap doan, tap quan, bai toan
toan ban » van ban

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((doi chieu) OR (ho chieu)) sach - thanh tung cua ((phuong cang) or (phuong giang)) tap toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (ho chieu)) sach - thanh tung cua ((phuong cang) OR (phuong giang)) tap toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) OR (ho chieu)) sach - thanh tung cua ((phuong cang) or (phuong giang)) tap toan ban".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) OR (ho chieu)) sach - thanh tung cua ((phuong cang) or (phuong giang)) tap toan ban*.