Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
xuc va » duc va, tuc va, luc 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: ((te sach) or (((toc sach) OR (doc sach)))) ky nang x hoi. hieu ve cam xuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (((toc sach) OR (doc sach)))) ky nang x hoi. hieu ve cam xuc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (((toc sach) OR (doc sach)))) ky nang x hoi. hieu ve cam xuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (((toc sach) OR (doc sach)))) ky nang x hoi. hieu ve cam xuc va hanh vi cua tre*.