Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
thanh va » thanh van, hanh va, thanh ha
vu sach » vu bach, su sach, vu khach
ky lang » ky dang, ky tang, tay lang
hieu ve » hieu va
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va
va cua » va chua, via cua, ca 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 ((ky lang) or (ky nang)) xa hoi. ((hieu ve) OR (hieu van)) coc luc va thanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ((ky lang) OR (ky nang)) xa hoi. ((hieu ve) OR (hieu van)) coc luc va thanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ((ky lang) or (ky nang)) xa hoi. ((hieu ve) OR (hieu van)) coc luc va thanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ((ky lang) or (ky nang)) xa hoi. ((hieu ve) OR (hieu van)) coc luc va thanh va cua tre*.