Perhaps you should try some spelling variations:
sach ty » sach y, sach tu, sach thu
vai cua » hai cua, lai cua, bai cua
va hanh » van hanh, va thanh, va danh
cac xuc » cam xuc, cac nuoc, chat xuc
qua cac » cua cac
vu sach » vu bach, su sach, vu khach
ty hang » ly hang, ty xang, thi hang
xuc va » duc va, tuc va, luc va
o hoc » co hoc, mo hoc, so hoc
o hoi » co hoi, o hai, o 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: vu sach ty hang ((o hoi) OR (o hoc)). hieu qua cac xuc va hanh ((vai cua) OR (dai cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty hang ((o hoi) OR (o hoc)). hieu qua cac xuc va hanh ((vai cua) or (dai cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: vu sach ty hang ((o hoi) OR (o hoc)). hieu qua cac xuc va hanh ((vai cua) or (dai cua)) tre*.