Perhaps you should try some spelling variations:
vu sach » vu bach, su sach, vu khach
sach ty » sach y, sach tu, sach thu
vai cua » hai cua, lai cua, bai cua
qua hai » qua hoat
ty nang » ky nang, ty xang, ty hang
luc va » duc va, tuc va, loc va
nang o » nang co, nang ho, nang ro
xuc va » duc va, tuc va, xac va
o hoi » co hoi, o hoc, o hai

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 nang o hoi. hieu qua hai ((xuc va) OR (luc va)) hanh ((vai cua) OR (dai cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty nang o hoi. hieu qua hai ((xuc va) OR (luc va)) hanh ((vai cua) or (dai cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: vu sach ty nang o hoi. hieu qua hai ((xuc va) OR (luc va)) hanh ((vai cua) or (dai cua)) tre*.