Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
va thanh » gia thanh, ban thanh, va tinh
thanh de » hanh de, thanh ve, thanh do
tu sach » su sach, te sach, tu cach
cao hoi » co hoi, cao hoc, tao hoi
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
de cua » le cua, te cua, dieu cua

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

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