Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hanh vai » hanh vi, hanh tai, hanh van
hanh va » hang va, hanh vi
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
va cam » va cham, va cac, va cao

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 ty ((nang xa) OR (nang ma)) hoi. lieu va cam duc van ((hanh vai) or (hanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ty ((nang xa) OR (nang ma)) hoi. lieu va cam duc van ((hanh vai) OR (hanh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ty ((nang xa) OR (nang ma)) hoi. lieu va cam duc van ((hanh vai) or (hanh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ty ((nang xa) OR (nang ma)) hoi. lieu va cam duc van ((hanh vai) or (hanh va)) cua tre*.