Perhaps you should try some spelling variations:
van khang » van khanh, van thanh, van quang
lam duoc » nam duoc, luat duoc, lam thuoc
van hang » van hoang, van thang, ban hang
thi hang » thi hanh, thi nang, thi hong
hieu van » hieu va, thien van, lieu va
te sach » toc sach
van lam » van nam
ty lang » tay lang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
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: te sach ((ty lang) or (thi hang)) xa hoi. hieu van lam duoc ((van hang) OR (van khang)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ty lang) OR (thi hang)) xa hoi. hieu van lam duoc ((van hang) OR (van khang)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ty lang) or (thi hang)) xa hoi. hieu van lam duoc ((van hang) OR (van khang)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((ty lang) or (thi hang)) xa hoi. hieu van lam duoc ((van hang) OR (van khang)) va cua tre*.