Perhaps you should try some spelling variations:
su sach » so sach, vu sach
ly nang » ky nang, ly hang, ly vang
hieu ve » hieu va, hieu van
cam tuc » cam tu, nam thuc, dam thuc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, v nang, may nang
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: su sach ((y nang) OR (ly nang)) x hoi. hieu ve ((cam tuc) or (cam xuc)) va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (ly nang)) x hoi. hieu ve ((cam tuc) OR (cam xuc)) va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y nang) OR (ly nang)) x hoi. hieu ve ((cam tuc) or (cam xuc)) va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) OR (ly nang)) x hoi. hieu ve ((cam tuc) or (cam xuc)) va hanh vi cua tre*.