Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
vat hanh » vat thanh, van hanh, va hanh
toc sach » hoc sach, doc sach, thuoc sach
van nham » van nam, van nhan, van tham
hieu van » hieu va, thien van, lieu va
so sach » so sanh, co sach, hoc sach
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
bo sach » co sach, hoc sach
di cua » dai cua, doi cua, de cua
ma hoi » mai hoi, xa hoi, ma hoa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((((so sach) OR (bo sach))) OR (toc sach)) ky sang ma hoi. hieu van nham thuc vat hanh di cua tre~.
• Adding a wildcard symbol may retrieve word variants: ((((so sach) or (bo sach))) or (toc sach)) ky sang ma hoi. hieu van nham thuc vat hanh di cua tre*.