Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cham duc » pham duc, cham soc, pham duy
tu sach » thu sach, su sach, te sach
ve cham » va cham, ve chat, vu cham
bai cua » ban cua, bai ca, hai cua
duc van » duc va, duc tan, duc manh
hieu ve » hieu va, hieu van
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach v nang ((x hoi) or (o hoi)). hieu ve cham duc van hanh ((bai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach v nang ((x hoi) OR (o hoi)). hieu ve cham duc van hanh ((bai cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: tu sach v nang ((x hoi) or (o hoi)). hieu ve cham duc van hanh ((bai cua) or (dai cua)) tre*.