Perhaps you should try some spelling variations:
nhung huong » nhung phuong, nhung tuong, nhung cong
trinh quan » tinh quang, trinh luat, trinh han
doi chieu » doc hieu, doi chi, mot chieu
trinh cua » tinh cua, trinh luat, trinh luan
ho chieu » theo chieu, hoc thieu, mot chieu
dan toan » van toan, dan than, manh 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 (doi chieu)) sach - hanh ((trinh cua) or (trinh quan)) nhung huong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chieu)) sach - hanh ((trinh cua) OR (trinh quan)) nhung huong dan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) OR (doi chieu)) sach - hanh ((trinh cua) or (trinh quan)) nhung huong dan toan cau".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) OR (doi chieu)) sach - hanh ((trinh cua) or (trinh quan)) nhung huong dan toan cau*.