Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach ty » sach y, sach tu, sach thu
ty lang » tay lang, ty xang, ty hang
lang xa » lang ha, dang xay, lang van
van dam » van nam, van dao, van dau
van lam » van nam
hanh va » hang va
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: toc sach ty lang xa hoi. hieu ((van dam) or (van lam)) duc va ((hanh va) OR (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty lang xa hoi. hieu ((van dam) OR (van lam)) duc va ((hanh va) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty lang xa hoi. hieu ((van dam) or (van lam)) duc va ((hanh va) OR (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ty lang xa hoi. hieu ((van dam) or (van lam)) duc va ((hanh va) OR (hanh vi)) cua tre*.