Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
hanh vai » hanh vi, hanh va, hanh tai
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa

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 ty xang xa hoi. ((hieu va) or (hieu van)) cam ((xuc va) OR (tuc va)) hanh vai cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty xang xa hoi. ((hieu va) OR (hieu van)) cam ((xuc va) OR (tuc va)) hanh vai cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty xang xa hoi. ((hieu va) or (hieu van)) cam ((xuc va) OR (tuc va)) hanh vai cua vat".
• Adding a wildcard symbol may retrieve word variants: tu sach ty xang xa hoi. ((hieu va) or (hieu van)) cam ((xuc va) OR (tuc va)) hanh vai cua vat*.