Perhaps you should try some spelling variations:
hieu luc » hieu luat, hieu qua
luc cham » luc tham, tuc cham, phuc cham
cham xuc » cam xuc, chat xuc, cham soc
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
sach tu » sach thu, cach tu, sach ty
tu xang » ty xang, tu lang, tu quang
xang xa » lang xa, mang xa, ang xa
vai cua » dai cua, hai cua, lai cua
vi cua » di cua

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 tu xang xa hoi. hieu luc cham xuc ((van hanh) or (ban hanh)) ((vi cua) or (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu xang xa hoi. hieu luc cham xuc ((van hanh) OR (ban hanh)) ((vi cua) OR (vai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: tu sach tu xang xa hoi. hieu luc cham xuc ((van hanh) or (ban hanh)) ((vi cua) or (vai cua)) tre*.