Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hanh vai » hanh vi, hanh va, hanh tai
vai cua » dai cua, hai cua, lai cua
xa hanh » xa thanh, xa khanh, va hanh
va tham » van tham, va cham, va thanh
ve chim » va chim, ve cham, ve chinh
ty nang » ky nang, ty xang, ty hang
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

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) or (su sach)) ty nang x hoi. hieu ((ve chim) or (va tham)) tuc xa hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (su sach)) ty nang x hoi. hieu ((ve chim) OR (va tham)) tuc xa hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (su sach)) ty nang x hoi. hieu ((ve chim) or (va tham)) tuc xa hanh vai cua tre*.