Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
chat xuc » chat huu, cam xuc, chao xu
hang vi » hanh vi, hang di, khang voi
xuc ban » duc ban, cuc ban, quoc ban
ve chat » va chat, van chat
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
mang xa » lang xa, mang may, dang xay
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ty ((mang xa) or (nang ma)) hoi. hieu ve chat xuc ban ((hang vi) or (hang va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ty ((mang xa) OR (nang ma)) hoi. hieu ve chat xuc ban ((hang vi) OR (hang va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: doc sach ty ((mang xa) or (nang ma)) hoi. hieu ve chat xuc ban ((hang vi) or (hang va)) cua tre*.