Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
tu sach » thu sach, su sach, te sach
nang xa » lang xa, nang ma, mang xa
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh
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 (hoc sach)) ky ((nang xa) or (nang x)) 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 (hoc sach)) ky ((nang xa) OR (nang x)) hoi. hieu ve cac duc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (hoc sach)) ky ((nang xa) or (nang x)) hoi. hieu ve cac duc va hanh vi cua tre*.