Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
te ban » te bao
vi cua » vai cua, di cua
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: ((((te sach) OR (toc sach))) or (te ban)) ky nang x hoi. hieu van tham thuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((te sach) OR (toc sach))) OR (te ban)) ky nang x hoi. hieu van tham thuc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((te sach) OR (toc sach))) or (te ban)) ky nang x hoi. hieu van tham thuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((((te sach) OR (toc sach))) or (te ban)) ky nang x hoi. hieu van tham thuc va hanh vi cua tre*.