Perhaps you should try some spelling variations:
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
hieu va » lieu va, hieu qua
cac duc » cac du, cac dac, cac nuoc
cao duc » dao duc, cao suc, giao duc
va hanh » van hanh, va thanh, va danh
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: su sach ty xang xa hoi. hieu va ((cac duc) or (cao duc)) va hanh ((vi cua) OR (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty xang xa hoi. hieu va ((cac duc) OR (cao duc)) va hanh ((vi cua) OR (vai cua)) tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty xang xa hoi. hieu va ((cac duc) or (cao duc)) va hanh ((vi cua) OR (vai cua)) tre*".