Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
van hang » van khang, van hoang, van thang
hoi cua » hoi chuc
hai cua » thai cua, dai cua, lai cua
xuc van » duc van, luc van, vuc van
va chat » van chat, va phat, cao chat
nang ma » tang ma, sang ma, nang cao
va cham » va tham
y nang » ky nang, ly nang, v nang
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: doc sach y nang ma hoi. lieu ((va cham) OR (va chat)) xuc van hang ((hai cua) OR (hoi cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach y nang ma hoi. lieu ((va cham) or (va chat)) xuc van hang ((hai cua) OR (hoi cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: doc sach y nang ma hoi. lieu ((va cham) or (va chat)) xuc van hang ((hai cua) OR (hoi cua)) tre*.