Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
sach thu » sach thue, sach thieu, sach tham
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
va tinh » may tinh
tinh di » tinh doi, trinh di, tinh da
cua tre » cua te, cuu tre, dua tren

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach thu ((nang x) or (nang cao)) hoi. hieu ve pham duc va tinh di ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu ((nang x) OR (nang cao)) hoi. hieu ve pham duc va tinh di ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thu ((nang x) or (nang cao)) hoi. hieu ve pham duc va tinh di ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: su sach thu ((nang x) or (nang cao)) hoi. hieu ve pham duc va tinh di ((cua tre) OR (cua triet))*.