Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
dieu tra » dieu tri, kiem tra
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
va cao » va cac, va co, va dao
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach v nang x hoi. lieu va cao ((luc va) OR (tuc va)) dang ((dieu cua) or (dieu tra)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach v nang x hoi. lieu va cao ((luc va) OR (tuc va)) dang ((dieu cua) OR (dieu tra)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach v nang x hoi. lieu va cao ((luc va) OR (tuc va)) dang ((dieu cua) or (dieu tra)) tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach v nang x hoi. lieu va cao ((luc va) OR (tuc va)) dang ((dieu cua) or (dieu tra)) tre*.