Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
sach thi » sach thu, sach tai, sach thieu
thi hang » thi hanh, thi nang, thi hong
kinh vai » kinh hai, kinh va, kinh van
te sach » toc sach
hang xa » hoang xa, hang va, hang ca
vai cua » dai cua, hai cua, lai cua
xuc va » duc va, tuc va, xac va
luc va » duc va, tuc va, loc va

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