Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van dinh » van minh, van dich, va dinh
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
va tinh » may tinh
cua tre » cua te, cuu tre, cua triet
cho xu » choi xu, cho xa, cho xe
va cua » va chua, via cua, ca 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 ky lang xa hoi. hieu van ((cho xu) OR (chao xu)) ((va tinh) or (van dinh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang xa hoi. hieu van ((cho xu) OR (chao xu)) ((va tinh) OR (van dinh)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky lang xa hoi. hieu van ((cho xu) OR (chao xu)) ((va tinh) or (van dinh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. hieu van ((cho xu) OR (chao xu)) ((va tinh) or (van dinh)) va cua tre*.