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

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y nang ((ma hoi) or (mai khoi)). hieu ve cau ((luc va) OR (tuc va)) hanh va cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ((ma hoi) OR (mai khoi)). hieu ve cau ((luc va) OR (tuc 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 khoi)). hieu ve cau ((luc va) OR (tuc va)) hanh va cua su".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((ma hoi) or (mai khoi)). hieu ve cau ((luc va) OR (tuc va)) hanh va cua su*.