Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van tuan » van quan, van ban, anh tuan
tuan xuc » quang xuc, tuan khuc, toan xac
tinh dai » trinh dai, tinh da, tinh hai
ty nang » ty xang, ty hang, ly nang
va tinh » may tinh
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va

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 ((ty nang) or (ky nang)) xa hoi. hieu van tuan xuc va tinh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty nang) OR (ky nang)) xa hoi. hieu van tuan xuc va tinh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((ty nang) or (ky nang)) xa hoi. hieu van tuan xuc va tinh dai cua tre*.