Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ban hanh » ban hang
cham cuu » chat cua
hieu van » hieu va, thien van, lieu va
dang van » hoang van, hang va
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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 y ((lang xa) or (dang van)) hoi. hieu van ((cham cuu) OR (cap cuu)) ban hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y ((lang xa) OR (dang van)) hoi. hieu van ((cham cuu) OR (cap cuu)) ban hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y ((lang xa) or (dang van)) hoi. hieu van ((cham cuu) OR (cap cuu)) ban hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y ((lang xa) or (dang van)) hoi. hieu van ((cham cuu) OR (cap cuu)) ban hanh vi cua tre*.