Perhaps you should try some spelling variations:
sinh dai » sinh thai, si dai, sinh vat
van sinh » van minh, va sinh, van dinh
sach ty » sach tu, sach thu, xach tay
van hac » van ha, van hai, van chat
van hoc » van hoa
cua tre » cua te, cuu tre, cua triet
xang x » nang x
du van » duy van, duc van, tu van
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: thu ((sach ty) OR (sach y)) xang x hoi. hieu ((van hac) or (van hoc)) du van sinh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ty) OR (sach y)) xang x hoi. hieu ((van hac) OR (van hoc)) du van sinh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ty) OR (sach y)) xang x hoi. hieu ((van hac) or (van hoc)) du van sinh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ty) OR (sach y)) xang x hoi. hieu ((van hac) or (van hoc)) du van sinh dai cua tre*.