Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tinh va » tich va, trinh van, trinh vat
tinh vi » trinh vi, tinh voi, dinh vi
cac duc » cac du, cao duc, cac dac
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
ve cac » va cac, vien cac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty nang xa hoi. hieu ve cac duc va ((tinh vi) OR (tinh va)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ty nang xa hoi. hieu ve cac duc va ((tinh vi) or (tinh va)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ty nang xa hoi. hieu ve cac duc va ((tinh vi) or (tinh va)) cua tre*.