Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
van bac » van ban, van bao, van hac
dac san » cac san, dac nhan
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang x hoi. hieu van bac ((dac san) OR (dac sac)) thanh dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang x hoi. hieu van bac ((dac san) OR (dac sac)) thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang x hoi. hieu van bac ((dac san) OR (dac sac)) thanh dai cua tre*.