Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
toc sach » hoc sach, doc sach, thuoc sach
hieu ve » hieu va, hieu van
danh vi » hanh vi, dinh vi, danh di
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
luc va » tuc va, loc va
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (toc sach)) ky nang x hoi. hieu ve cac ((luc va) OR (duc va)) danh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (toc sach)) ky nang x hoi. hieu ve cac ((luc va) OR (duc va)) danh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (toc sach)) ky nang x hoi. hieu ve cac ((luc va) OR (duc va)) danh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (toc sach)) ky nang x hoi. hieu ve cac ((luc va) OR (duc va)) danh vi cua tre*.