Perhaps you should try some spelling variations:
quang tran » quang tuan, quang trung, quang thanh
phung cong » nhung cong, phong cong, nhung chong
hung cuong » hung vuong, hong cuong, hung luong
doi chieu » doi chi, mot chieu, ho chieu
doc hieu » toc thieu, hoc thieu, hoc hien
bai toan » bai tap
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: ((doi chieu) OR (doc hieu)) sach - nhanh quang tran ((phung cong) or (hung cuong)) bai toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (doc hieu)) sach - nhanh quang tran ((phung cong) OR (hung cuong)) bai toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) OR (doc hieu)) sach - nhanh quang tran ((phung cong) or (hung cuong)) bai toan cau".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) OR (doc hieu)) sach - nhanh quang tran ((phung cong) or (hung cuong)) bai toan cau*.