Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu ve » hieu va, hieu van
xuc gia » duc gia, tuc gia, quoc gia
luc gia » luoc gia, duc gia, quoc gia
y nang » ky nang, ly nang, v nang
ve cac » va cac, vien cac
ve cau » va cau, le cau, ve cai
ke cau » ket cau

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: toc sach y nang x ho. hieu ve cac ((xuc gia) OR (luc gia)) thanh ((ve cau) OR (ke cau)) treo~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang x ho. hieu ve cac ((xuc gia) OR (luc gia)) thanh ((ve cau) or (ke cau)) treo~".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang x ho. hieu ve cac ((xuc gia) OR (luc gia)) thanh ((ve cau) or (ke cau)) treo*.