Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
su sach » so sach, vu sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
thu va » thuc va, thue va, tu 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: su sach ly nang x hoi. hieu ((vien cac) or (va cac)) thu va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly nang x hoi. hieu ((vien cac) OR (va cac)) thu va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ly nang x hoi. hieu ((vien cac) or (va cac)) thu va hanh vi cua tre*.