Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
da nang » cam nang, kha nang, cao nang
vu nang » vuc nang, va nang, vu dang
hang di » hang doi, hang vi, hang dien
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va
loc va » hoc va
di cua » dai cua, doi cua, de cua

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

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