Perhaps you should try some spelling variations:
chau cuu » cham cuu, cap cuu, chau au
su sach » so sach, vu sach
sach tu » sach thu, cach tu, sach ty
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
va dinh » van dinh, va kinh, vu dinh
va tinh » may tinh
cuu tre » cua tre, cau tren, cau treo

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 tu ((nang x) or (nang cao)) hoi. hieu va pham duc ((va dinh) OR (va tinh)) chau cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu ((nang x) OR (nang cao)) hoi. hieu va pham duc ((va dinh) OR (va tinh)) chau cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu ((nang x) or (nang cao)) hoi. hieu va pham duc ((va dinh) OR (va tinh)) chau cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach tu ((nang x) or (nang cao)) hoi. hieu va pham duc ((va dinh) OR (va tinh)) chau cuu tre*.