Perhaps you should try some spelling variations:
te sach » toc sach
hanh va » hang va, hanh vi
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
y nang » ky nang, ly nang, v nang
ve cau » ke cau, va cau, ve cac
luc va » tuc va, loc va
ma hoi » xa hoi, ma hoa, me hoi
va cua » va chua, via cua, ca cua
cua su » qua su

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: te sach y nang ((ma hoi) OR (mai hoi)). hieu ve cau ((luc va) OR (duc va)) hanh va cua su~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ((ma hoi) or (mai hoi)). hieu ve cau ((luc va) OR (duc va)) hanh va cua su~".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((ma hoi) or (mai hoi)). hieu ve cau ((luc va) OR (duc va)) hanh va cua su*.