Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van than » van thanh, van thang, van tuan
than duc » tran duc, phan duc, than doc
va thanh » gia thanh, ban thanh, va tinh
nang xa » nang x, lang xa, nang ma
vai cua » hai cua, lai cua, mai cua
bai cua » ban cua, bai ca, hai cua
sach 2 » sach y
2 nang » v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach 2 nang xa hoi. hieu van than duc va thanh ((((vai cua) OR (bai cua))) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach 2 nang xa hoi. hieu van than duc va thanh ((((vai cua) OR (bai cua))) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach 2 nang xa hoi. hieu van than duc va thanh ((((vai cua) OR (bai cua))) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach 2 nang xa hoi. hieu van than duc va thanh ((((vai cua) OR (bai cua))) or (dai cua)) tre*.