Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
lang xa » lang ha, dang xay, lang van
nang ma » tang ma, sang ma, nang cao
van cac » van hac, van cau, van bac
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
nang xa » nang x, mang xa, ang xa
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach y ((((nang xa) or (lang xa))) or (nang ma)) hoi. hieu van cac tuc va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach y ((((nang xa) OR (lang xa))) OR (nang ma)) hoi. hieu van cac tuc va hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach y ((((nang xa) or (lang xa))) or (nang ma)) hoi. hieu van cac tuc va hanh vai cua tre*.