Perhaps you should try some spelling variations:
vu sach » vu bach, vu khach
va hanh » van hanh, va thanh, va danh
cac luc » cau luc, coc luc, cac nuoc
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
nang xa » lang xa, nang ma, mang xa
su sach » so sach
ve cac » va cac, vien cac
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua

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

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