Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, tu cach
va hanh » van hanh, va thanh, va danh
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
lang xa » lang ha, dang xay, lang van
te sach » toc sach
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
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: ((tu sach) or (te sach)) ky ((lang xa) or (tang ma)) hoi. hieu ve cac duc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky ((lang xa) OR (tang ma)) hoi. hieu ve cac duc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky ((lang xa) or (tang ma)) hoi. hieu ve cac duc va hanh vi cua tre*.