Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
ban hanh » ban hang
sach ky » sac ky, sach y, sach ty
cam tuc » cam xuc, cam tu, nam thuc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
vi cua » vai cua, di cua
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky nang ((xa hoi) or (o hoi)). hieu va cam tuc ((ban hanh) or (va thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang ((xa hoi) OR (o hoi)). hieu va cam tuc ((ban hanh) OR (va thanh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang ((xa hoi) or (o hoi)). hieu va cam tuc ((ban hanh) or (va thanh)) vi cua tre*.