Perhaps you should try some spelling variations:
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va, hieu qua
va cao » va cac, va co, va dao
xuc va » tuc va, luc va, xac va
vi cua » vai cua
di cua » dai cua, doi cua, de cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky dang xa hoi. hieu va cao ((xuc va) OR (duc va)) thanh ((vi cua) or (di cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky dang xa hoi. hieu va cao ((xuc va) OR (duc va)) thanh ((vi cua) OR (di cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky dang xa hoi. hieu va cao ((xuc va) OR (duc va)) thanh ((vi cua) or (di cua)) tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky dang xa hoi. hieu va cao ((xuc va) OR (duc va)) thanh ((vi cua) or (di cua)) tre*.