Perhaps you should try some spelling variations:
vu sach » vu bach, su sach, vu khach
so sanh » do sanh
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan 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 (so sanh)) ky dang xa hoi. hieu va cac duc va dan vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (so sanh)) ky dang xa hoi. hieu va cac duc va dan vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (so sanh)) ky dang xa hoi. hieu va cac duc va dan vi cua tre*.