Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cam duc » cam xuc, cao duc, pham duc
hanh di » hanh de, hang di, danh di
duc van » duc va, duc tan, duc manh
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam
x hoi » xa hoi, o hoi, x ho

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: ((te sach) OR (toc sach)) ky nang x hoi. hieu ve cam duc van ((hanh di) OR (hanh vi)) cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky nang x hoi. hieu ve cam duc van ((hanh di) OR (hanh vi)) cuu tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang x hoi. hieu ve cam duc van ((hanh di) OR (hanh vi)) cuu tre*.