Perhaps you should try some spelling variations:
duong tong » duong trong, duong cong, duong hong
hoc thieu » toc thieu, hoc hien
tran tuan » tran quang, tran thanh, tranh luan
tran xuan » tran quang, tran van
ho chieu » theo chieu, doi chieu, mot chieu
tong tap » tuong tac, trong tan, cong tac
tap toan » tap doan, tap quan, bai 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: ((ho chieu) or (hoc thieu)) sach - thanh ((tran tuan) OR (tran xuan)) duong tong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) sach - thanh ((tran tuan) OR (tran xuan)) duong tong tap toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (hoc thieu)) sach - thanh ((tran tuan) OR (tran xuan)) duong tong tap toan cau".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (hoc thieu)) sach - thanh ((tran tuan) OR (tran xuan)) duong tong tap toan cau*.