Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
tran anh » tran manh, tuan anh, tran thanh
toan anh » toan hanh, tuan anh, toan doanh
cao duc » dao duc, cao suc, giao duc
hieu va » lieu va, hieu qua
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (thu hoach)) ky tang xa hoi. hieu va cao duc ((toan anh) OR (tran anh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thu hoach)) ky tang xa hoi. hieu va cao duc ((toan anh) OR (tran anh)) vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thu hoach)) ky tang xa hoi. hieu va cao duc ((toan anh) OR (tran anh)) vi cua tre*".