Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
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
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
bo sach » co sach, hoc sach
vi cua » vai cua, di 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 nang ma hoi. hieu van nham thuc va hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((so sach) OR (bo sach))) or (toc sach)) ky nang ma hoi. hieu van nham thuc va hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((((so sach) OR (bo sach))) or (toc sach)) ky nang ma hoi. hieu van nham thuc va hanh vi cua tre*.