Perhaps you should try some spelling variations:
thien van » thi van
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, lieu va, hieu ve
sach ty » sach y, sach tu, sach thu
xang x » nang x
du van » duy van, duc van, vu van
tu van » tu va
vi cua » vai cua, di cua
cua te » cua tu
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: thu sach ty xang x hoi. ((hieu van) or (thien van)) hac ((du van) OR (tu van)) hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty xang x hoi. ((hieu van) OR (thien van)) hac ((du van) OR (tu van)) hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty xang x hoi. ((hieu van) or (thien van)) hac ((du van) OR (tu van)) hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ty xang x hoi. ((hieu van) or (thien van)) hac ((du van) OR (tu van)) hanh vi cua te*.