Perhaps you should try some spelling variations:
thien van » thi van
tru nang » tra nang, tri nang, truc nano
sach tru » sach truc, sach thu, sach tu
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
suc va » duc va, tuc va, soc va
luc va » duc va, tuc va, loc va
anh va » hanh va
va cua » va chua, via cua, ca cua
cua te » cua tu

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 tru nang xa hoi. ((hieu va) or (thien van)) cao ((suc va) OR (luc va)) anh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tru nang xa hoi. ((hieu va) OR (thien van)) cao ((suc va) OR (luc va)) anh va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tru nang xa hoi. ((hieu va) or (thien van)) cao ((suc va) OR (luc va)) anh va cua te".
• Adding a wildcard symbol may retrieve word variants: tu sach tru nang xa hoi. ((hieu va) or (thien van)) cao ((suc va) OR (luc va)) anh va cua te*.